General Security

Security Questions are Bullshit

 

I’m pretty much unhappy with the use of “Security Questions” – things like “what’s your mother’s maiden name”, or “what was your first pet”. These questions are sometimes used to strengthen an existing authentication control (e.g. “you’ve entered your password on a device that wasn’t recognised, from a country you normally don’t visit – please answer a security question”), but far more often they are used as a means to recover an account after the password has been lost, stolen or changed.

 

I’ve been asked a few times, given that these are pretty widely used, to explain objectively why I have such little disregard for them as a security measure. Here’s the Too Long; Didn’t Read summary:

  1. Most questions are equivalent to a low-entropy password
  2. Answers to many of these questions can be found online in public documents
  3. Answers can be squeezed out of you, by fair means or foul
  4. The same questions – and answers – are shared at multiple sites
  5. Questions (and answers) don’t get any kind of regulatory protection
  6. Because the best answers are factual and unchanging, you cannot change them if they are exposed

Let’s take them one by one:

Questions are like a low-entropy password

What’s your favourite colour? Blue, or Green. At the outside, red, yellow, orange or purple. That covers most people’s choices, in less than 3 bits of entropy.

What’s your favourite NBA team? There’s 29 of those – 30, if you count the 76ers. That’s 6 bits of entropy.

Obviously, there are questions that broaden this, but are relatively easy to guess with a small number of tries – particularly when you can use the next fact about Security Questions.

The Answers are available online

What’s your mother’s maiden name? It’s a matter of public record.

What school did you go to? If we know where you grew up, it’s easy to guess this, since there were probably only a handful of schools you could possibly have attended.

Who was your first boyfriend/girlfriend? Many people go on about this at length in Facebook posts, I’m told. Or there’s this fact:

You’ll tell people the answers

What’s your porn name? What’s your Star Wars name? What’s your Harry Potter name?

All these stupid quizzes, and they get you to identify something about yourself – the street you grew up on, the first initial of your secret crush, how old you were when you first heard saxophones.

And, of course, because of the next fact, all I really have to do is convince you that you want a free account at my site.

Answers are shared everywhere

Every site that you visit asks you variants of the same security questions – which means that you’ll have told multiple sites the same answers.

You’ve been told over and over not to share your password across multiple sites – but here you are, sharing the security answers that will reset your password, and doing so across multiple sites that should not be connected.

And do you think those answers (and the questions they refer back to) are kept securely by these various sites? No, because:

Questions & Answers are not protected like passwords

There’s regulatory protection, under regimes such as PCI, etc, telling providers how to protect your passwords.

There is no such advice for protecting security questions (which are usually public) and the answers to them, which are at least presumed to be stored in a back-end database, but are occasionally sent to the client for comparison against the answers! That’s truly a bad security measure, because of course you’re telling the attacker.

Even assuming the security answers are stored in a database, they’re generally stored in plain text, so that they can be accessed by phone support staff to verify your answers when you call up crying that you’ve forgotten your password. [Awesome pen-testing trick]

And because the answers are shared everywhere, all it takes is a breach at one provider to make the security questions and answers they hold have no security value at all any more.

If they’re exposed, you can’t change them

There’s an old joke in security circles, “my password got hacked, and now I have to rename my dog”. It’s really funny, because there are so many of these security answers which are matters of historical fact – while you can choose different questions, you can’t generally choose a different answer to the same question.

Well, obviously, you can, but then you’ve lost the point of a security question and answer – because now you have to remember what random lie you used to answer that particular question on that particular site.

And for all you clever guys out there…

Yes, I know you can lie, you can put in random letters or phrases, and the system may take them (“Your place of birth cannot contain spaces” – so, Las Vegas, New York, Lake Windermere are all unusable). But then you’ve just created another password to remember – and the point of these security questions is to let you log on once you’ve forgotten your password.

So, you’ve forgotten your password, but to get it back, you have to remember a different password, one that you never used. There’s not much point there.

In summary

Security questions and answers, when used for password recovery / reset, are complete rubbish.

Security questions are low-entropy, predictable and discoverable password substitutes that are shared across multiple sites, are under- or un-protected, and (like fingerprints) really can’t be changed if they become exposed. This makes them totally unsuited to being used as password equivalents in account recovery / password reset schemes.

If you have to implement an account recovery scheme, find something better to use. In an enterprise, as I’ve said before, your best bet is to use something that the enterprise does well – the management hierarchy. Every time you forget your password, you have to get your manager, or someone at the next level up from them, to reset your password for you, or to vouch for you to tech support. That way, someone who knows you, and can affect your behaviour in a positive way, will know that you keep forgetting your password and could do with some assistance. In a social network, require the

Password hints are bullshit, too

Also, password hints are bullshit. Many of the Adobe breach’s “password hints” were actually just the password in plain-text. And, because Adobe didn’t salt their password hashes, you could sort the list of password hashes, and pick whichever of the password hints was either the password itself, or an easy clue for the password. So, even if you didn’t use the password hint yourself, or chose a really cryptic clue, some other idiot came up with the same password, and gave a “Daily Express Quick Crossword” quality clue.

How to do password reset

First, a quick recap:

Credentials include a Claim and a Proof (possibly many).

The Claim is what states one or more facts about your identity.

A Username is one example of a Claim. So is Group Membership, Age, Eye Colour, Operating System, Installed Software, etc…

The Proof is what allows someone to reliably trust the Claim is true.

A Password is one example of a Proof. So is a Signature, a Passport, etc…

Claims are generally public, or at least non-secret, and if not unique, are at least specific (e.g. membership of the group “Brown eyes” isn’t open to people with blue eyes).

Proofs are generally secret, and may be shared, but such sharing should not be discoverable except by brute force. (Which is why we salt passwords).

Now, the topic – password resets

Password resets can occur for a number of reasons – you’ve forgotten your password, or the password change functionality is more cumbersome than the password reset, or the owner of the account has changed (is that allowable?) – but the basic principle is that an account needs a new password, and there needs to be a way to achieve that without knowledge of the existing password.

Let’s talk as if it’s a forgotten password.

So we have a Claim – we want to assert that we possess an identity – but we have to prove this without using the primary Proof.

Which means we have to know of a secondary Proof. There are common ways to do this – alternate ID, issued by someone you trust (like a government authority, etc). It’s important in the days of parody accounts, or simply shared names (is that Bob Smith, his son, Bob Smith, or his unrelated neighbour, Bob Smith?) that you have associated this alternate ID with the account using the primary Proof, or as a part of the process of setting up the account with the primary Proof. Otherwise, you’re open to account takeover by people who share the same name as their target.

And you can legally change your name.

What’s the most common alternate ID / secondary Proof?

E-mail.

Pretty much every public web site relies on the use of email for password reset, and uses that email address to provide a secondary Proof.

It’s not enough to know the email address – that’s unique and public, and so it matches the properties of a Claim, not a Proof, of identity.

We have to prove that we own the email address.

It’s not enough to send email FROM the email address – email is known to be easily forged, and so there’s no actual proof embodied in being able to send an email.

That leaves the server with the prospect of sending something TO the email address, and the recipient having proved that they received it.

You could send a code-word, and then have the recipient give you the code-word back. A shared secret, if you like.

And if you want to do that without adding another page to the already-too-large security area of the site, you look for the first place that allows you to provide your Claim and Proof, and you find the logon page.

By reusing the logon page, you’re going to say that code-word is a new password.

[This is not to say that email is the only, or even the best, way to reset passwords. In an enterprise, you have more reliable proofs of identity than an email provider outside of your control. You know people who should be able to tell you with some surety that a particular person is who they claim to be. Another common secondary identification is the use of Security Questions. See my upcoming article, “Security Questions are Bullshit” for why this is a bad idea.]

So it’s your new password, yes?

Well, yes and no. No, actually. Pretty much definitely no, it’s not your new password.

Let’s imagine what can go wrong. If I don’t know your password, but I can guess your username (because it’s not secret), I can claim to be you wanting to reset your password. That not only creates opportunity for me to fill your mailbox with code-words, but it also prevents you from logging on while the code-words are your new password. A self-inflicted denial of service.

So your old password should continue working, and if you never use the code-word, because you’re busy ignoring and deleting the emails that come in, it should keep working for you.

I’ve frequently encountered situations in my own life where I’ve forgotten my password, gone through the reset process, and it’s only while typing in the new password, and being told what restrictions there are on characters allowed in the new password, that I remember what my password was, and I go back to using that one.

In a very real sense, the code-word sent to you is NOT your new password, it’s a code-word that indicates you’ve gone the password reset route, and should be given the opportunity to set a new password.

Try not to think of it as your “temporary password”, it’s a special flag in the logon process, just like a “duress password”. It doesn’t replace your actual password.

It’s a shared secret, so keep it short-lived

Shared secrets are fantastic, useful, and often necessary – TLS uses them to encrypt data, after the initial certificate exchange.

But the trouble with shared secrets is, you can’t really trust that the other party is going to keep them secret very long. So you have to expire them pretty quickly.

The same is true of your password reset code-word.

In most cases, a user will forget their password, click the reset link, wait for an email, and then immediately follow the password reset process.

Users are slow, in computing terms, and email systems aren’t always directly linked and always-connected. But I see no reason why the most usual automated password reset process should allow the code-word to continue working after an hour.

[If the process requires a manual step, you have to count that in, especially if the manual step is something like “contact a manager for approval”, because managers aren’t generally 24/7 workers, the code-word is going to need to last much longer. But start your discussion with an hour as the base-point, and make people fight for why it’ll take longer to follow the password reset process.]

It’s not a URL

You can absolutely supply a URL in the email that will take the user to the right page to enter the code-word. But you can’t carry the code-word in the URL.

Why? Check out these presentations from this year’s Black Hat and DefCon, showing the use of a malicious WPAD server on a local – or remote – network whose purpose is to trap and save URLs, EVEN HTTPS URLs, and their query strings.

Every URL you send in an email is an HTTP or HTTPS GET, meaning all the parameters are in the URL or in the query string portion of the URL.

This means the code-word can be sniffed and usurped if it’s in the URL. And the username is already assumed to be known, since it’s a non-secret. [Just because it’s assumed to be known, don’t give the attacker an even break – your message should simply say “you requested a password reset on an account at our website” – a valid request will come from someone who knows which account at your website they chose to request.]

So, don’t put the code-word in the URL that you send in the email.

Log it, and watch for repeats, errors, other bad signs

DON’T LOG THE PASSWORD

I have to say that, because otherwise people do that, as obviously wrong as it may seem.

But log the fact that you’ve changed a password for that user, along with when you did it, and what information you have about where the user reset their password from.

Multiple users resetting their password from the same IP address – that’s a bad sign.

The same user resetting their password multiple times – that’s a bad sign.

Multiple expired code-words – that’s a bad sign.

Some of the bad things being signaled include failures in your own design – for instance, multiple expired code-words could mean that your password reset function has stopped working and needs checking. You have code to measure how many abandoned shopping carts you have, so include code that measures how many abandoned password reset attempts you have.

In summary, here’s how to do email password reset properly

  1. Consider whether email is an appropriately reliable secondary proof of identification.
    1. A phone call from the user, to their manager, followed by the manager resetting the user’s password is trustworthy, and self-correcting. A little slow and awkward, but stronger.
    2. Other forms of identification are almost all stronger and more resistant to forgery and attack than email.
    3. Bear in mind that, by trusting to email, you’re trusting that someone who just forgot their password can remember their other password, and hasn’t shared it, or used an easily-guessed password.
  2. When an account is created, associate it with an email address, and allow & encourage the validated account holder to keep that updated.
  3. Allow anyone to begin a password reset process – but don’t allow them to repeatedly do so, for fear of allowing DoS attacks on your users.
  4. When someone has begun a password reset process, send the user a code-word in email. This should be a random sequence, of the same sort of entropy as your password requirements.
    1. Encoding a time-stamp in the code-word is useful.
    2. Do not put the code-word in a URL in the message.
    3. Do not specify the username in the message, not even in the URL.
  5. Do not change the user’s password for them yet. This code-word is NOT their new password.
  6. Wait for up to an hour (see item 4.1. – the time stamp) during which you’ll accept the code-word. Be very cautious about extending this period.
  7. The code-word, when entered at the password prompt for the associated user, is an indication to change the password, and that’s ALL it can be used for.
  8. Allow the user to cancel out of the password change, up to the point where they have entered a new password and its verification code and hit OK.

And here’s how you’re going to screw it up (don’t do these!)

  • You’ll use email for password resets on a high-security account. Email is relatively low-security.
  • You’ll use email when there’s something more reliable and/or easier to use, because “it’s what everyone does”.
  • You’ll use email to an external party with whom you don’t have a business relationship, as the foundation on which you build your corporate identity tower of cards.
  • You won’t have a trail of email addresses associated with the user, so you don’t have reason to trust you’re emailing the right user, and you won’t be able to recover when an email address is hacked/stolen.
  • You’ll think the code-word is a new password, leading to:
    • Not expiring the code-word.
    • Sending passwords in plain-text email (“because we already do it for password reset”).
    • Invalidating the user’s current password, even though they didn’t want it reset.
  • You’ll include the credentials (username and/or password) in a URL in the email message, so it can be picked up by malicious proxies.
  • You’ll fail to notice that someone’s DoSing some or all of your users by repeatedly initiating a password reset.
  • You’ll fail to notice that your password reset process is failing, leading to accounts being dropped as people can no longer get in.
  • You won’t include enough randomness in your code-word, so an attacker can reset two accounts at once – their own, and a victim’s, and use the same code-word to unlock both.
  • You’ll rely on security questions
  • You’ll use a poor-quality generation on your code-words, leading to easy predictability, reuse, etc.
  • You won’t think about other ways that your design will fail outside of this list here.

Let the corrections begin!

Did I miss something, or get something wrong? Let me know by posting a comment!

The Automatic Gainsaying of Anything the Other Person Says

Sometimes I think that title is the job of the Security Engineer – as a Subject Matter Expert, we’re supposed to meet with teams and tell them how their dreams are going to come crashing down around their ears because of something they hadn’t thought of, but which is obvious to us.

This can make us just a little bit unpopular.

But being argumentative and sceptical isn’t entirely a bad trait to have.

Sometimes it comes in handy when other security guys spread their various statements of doom and gloom – or joy and excitement.

Examples in a single line

“Rename your administrator account so it’s more secure” – or lengthen the password and achieve the exact same effect without breaking scripts or requiring extra documentation so people know what the administrator is called this week.

“Encrypt your data at rest by using automatic database encryption” – which means any app that authenticates to the database can read that data back out, voiding the protection that was the point of encrypting at rest. If fields need encrypting, maybe they need field-level access control, too.

“Complex passwords, one lower case, one upper case, one number, one symbol, no repeated letters” – or else, measure strength in more interesting ways, and display to users how strong their password is, so that a longish phrase, used by a competent typist, becomes an acceptable password.

Today’s big example – password expiration

Now I’m going to commit absolute heresy, as I’m going against the biggest recent shock news in security advice.

capture20160919063258336capture20160919063534856

I understand the arguments, and I know I’m frequently irritated with the unnecessary requirements to change my password after sixty days, and even more so, I know that the reasons behind password expiration settings are entirely arbitrary.

But…

There’s a good side to password expiry.

capture20160919063926113

These aren’t the only ways in which passwords are discovered.

The method that frequently gets overlooked is when they are deliberately shared.

Sharing means scaring

“Bob’s out this week, because his mother died, and he has to arrange details in another state. He didn’t have time to set up access control changes before he left, but he gave me a sticky-note with his password on it, so that we don’t need to bother him for anything”

“Everyone on this team has to monitor and interact with so many shared service accounts, we just print off a list of all the service account passwords. You can photocopy my laminated card with the list, if you like.”

Yes, those are real situations I’ve dealt with, and they have some pretty obvious replacement solutions:

Bob

Bob (or Bob’s manager, if Bob is too distraught to talk to anyone, which isn’t at all surprising) should notify a system administrator who can then respond to requests to open up ACLs as needed, rather than someone using Bob’s password. But he didn’t.

When Bob comes back, is he going to change his password?

No, because he trusts his assistant, Dave, with his communications.

But, of course, Dave handed out his password to the sales VP, because it was easier for him than fetching up the document she wanted. And sales VPs just can’t be trusted. Now the entire sales team knows Bob’s password. And then one of them gets fired, or hired on at a new competitor. The temptation to log on to Bob’s account – just once – is immense, because that list of customers is just so enticing. And really, who would ever know? And if they did know, everyone has Bob’s password, so it’s not like they could prosecute you, because they couldn’t prove it was you.

What’s going to save Bob is if he is required to change his password when he returns.

Laminated Password List

Yes, this also happened. Because we found the photocopy of the laminated sheet folded up on the floor of a hallway outside the lavatory door.

There was some disciplining involved. Up to, and possibly including, the termination of employment, as policy allows.

Then the bad stuff happened.

The team who shared all these passwords pointed out that, as well as these being admin-level accounts, they had other special privileges, including the avoidance of any requirement to change passwords.

These passwords hadn’t changed in six years.

And the team had no idea what would break if they changed the passwords.

Maybe one of those passwords is hard-coded into a script somewhere, and vital business processes would grind to a halt if the password was changed.

When I left six months later, they were still (successfully) arguing that it would be too dangerous to try changing the passwords.

To change a behaviour, you must first accept it

I’m not familiar with any company that acknowledges in policy that users share passwords, nor the expected behaviour when they do [log when you shared it, and who you shared it with, then change it as soon as possible after it no longer needs to be shared].

Once you accept that passwords are shared for valid reasons, even if you don’t enumerate what those reasons are, you can come up with processes and tools to make that sharing more secure.

If there was a process for Bob to share with Dave what his password is, maybe outlining the creation of a temporary password, reading Dave in on when Dave can share the password (probably never), and how Dave is expected to behave, and becomes co-responsible for any bad things done in Bob’s account, suddenly there’s a better chance Dave’s not going to share. “I can’t give you Bob’s password, but I can get you that document you’re after”

If there was a tool in which the team managing shared service accounts could find and unlock access to passwords, that tool could also be configured to distribute changed passwords to the affected systems after work had been performed.

Without acceptance, it is expiry which saves you

If you don’t have these processes or tools, the only protection you have against password sharing (apart from the obviously failing advice to “just don’t do it”) is regular password expiry.

Password expiry as a Business Continuity Practice

I’m also fond of talking about password expiration as being a means to train your users.

Do you even know how to change your passwords?

Certificates expire once a year, and as a result, programmers write code as if it’s never going to happen. After all, there’s plenty of time between now and next year to write the “renew certificate” logic, and by the time it’s needed, I’ll be working on another project anyway.

If passwords don’t expire – or don’t expire often enough – users will not have changed their password anything like recently enough to remember how to do so if they have to in an emergency.

So, when a keylogger has been discovered to be caching all the logons in the conference room, or the password hashes have been posted on Pastebin, most of your users – even the ones approving the company-wide email request for action – will fight against a password change request, because they just don’t know how to do it, or what might break when they do.

Unless they’ve been through it before, and it were no great thing. In which case, they’ll briefly sigh, and then change their password.

So, password expiry – universally good?

This is where I equivocate and say, yes, I broadly think the advice to reduce or remove password expiration is appropriate. My arguments above are mainly about things we’ve forgotten to remember that are reasons why we might have included password expiry to begin with.

Here, in closing, are some ways in which password expiry is bad, just to balance things out:

  • Some people guard their passwords closely, and generate secure passwords, or use hardware token devices to store passwords. These people should be rewarded for their security skills, not punished under the same password expiry regimen as the guy who adds 1 to his password, and is now up to “p@55w0rd73”.
  • Expiring passwords too frequently drives inexorably to “p@55word73”, and to password reuse across sites, as it takes effort to think up complex passwords, and you’re not going to waste that effort thinking up unique words every couple of months.
  • Password expiration often means that users spend significant time interrupted in their normal process, by the requirement to think up a password and commit it to the multiple systems they use.

Where do we stand?

Right now, this is where we stand:

  • Many big security organisations – NIST, CESG, etc – talk about how password expiry is an outdated and unnecessary concept
  • I think they’re missing some good reasons why password expiry is in place (and some ways in which that could be fixed)
  • Existing security standards that businesses are expected to comply with have NOT changed their stance.

As a result, especially of this last item, I don’t think businesses can currently afford to remove password expiry from their accounts.

But any fool can see which way the wind is blowing – at some point, you will be able to excuse your company from password expiry, but just in case your compliance standard requires it, you should have a very clear and strong story about how you have addressed the risks that were previously resolved by expiring passwords as frequently as once a quarter.

Explaining Blockchains – without understanding them.

I tweeted this the other day, after reading about Microsoft’s Project Bletchley:

I’ve been asked how I can tweet something as specific as this, when in a subsequent tweet, I noted:

[I readily admit I didn’t understand the announcement, or what it’s /supposed/ to be for, but that didn’t stop me thinking about it]

— Alun Jones (@ftp_alun) June 17, 2016

Despite having  reasonably strong background in the use of crypto, and a little dabbling into the analysis of crypto, I don’t really follow the whole “blockchain” thing.

So, here’s my attempt to explain what little I understand of blockchains and their potential uses, with an open invitation to come and correct me.

What’s a blockchain used for?

The most widely-known use of blockchains is that of Bit Coin and other “digital currencies”.

Bit Coins are essentially numbers with special properties, that make them progressively harder to find as time goes on. Because they are scarce and getting scarcer, it becomes possible for people of a certain mindset to ascribe a “value” to them, much as we assign value to precious metals or gemstones aside from their mere attractiveness. [Bit Coins have no intrinsic attractiveness as far as I can tell] That there is no actual intrinsic value leads me to refer to Bit Coin as a kind of shared madness, in which everyone who believes there is value to the Bit Coin shares this delusion with many others, and can use that shared delusion as a basis for trading other valued objects. Of course, the same kind of shared madness is what makes regular financial markets and country-run money work, too.

Because of this value, people will trade them for other things of value, whether that’s shiny rocks, or other forms of currency, digital or otherwise. It’s a great way to turn traceable goods into far less-traceable digital commodities, so its use for money laundering is obvious. Its use for online transactions should also be obvious, as it’s an irrevocable and verifiable transfer of value, unlike a credit card which many vendors will tell you from their own experiences can be stolen, and transactions can be revoked as a result, whether or not you’ve shipped valuable goods.

What makes this an irrevocable and verifiable transfer is the principle of a “blockchain”, which is reported in a distributed ledger. Anyone can, at any time, at least in theory, download the entire history of ownership of a particular Bit Coin, and verify that the person who’s selling you theirs is truly the current and correct owner of it.

How does a blockchain work?

I’m going to assume you understand how digital signatures work at this point, because that’s a whole ‘nother explanation.

Remember that a Bit Coin starts as a number. It could be any kind of data, because all data can be represented as a number. That’s important, later.

The first owner of that number signs it, and then distributes the number and signature out to the world. This is the “distributed ledger”. For Bit Coins, the “world” in this case is everyone else who signs up to the Bit Coin madness.

When someone wants to buy that Bit Coin (presumably another item of mutually agreed similar value exchanges hands, to buy the Bit Coin), the seller signs the buyer’s signature of the Bit Coin, acknowledging transfer of ownership, and then the buyer distributes that signature out to the distributed ledger. You can now use the distributed ledger at any time to verify that the Bit Coin has a story from creation and initial signature, unbroken, all the way up to current ownership.

I’m a little flakey on what, other than a search in the distributed ledger for previous sales of this Bit Coin, prevents a seller from signing the same Bit Coin over simultaneously to two other buyers. Maybe that’s enough – after all, if the distributed ledger contains a demonstration that you were unreliable once, your other signed Bit Coins will presumably have zero value.

So, in this perspective, a blockchain is simply an unbroken record of ownership or provenance of a piece of data from creation to current owner, and one that can be extended onwards.

In the world of financial use, of course, there are some disadvantages – the most obvious being that if I can make you sign a Bit Coin against your well, it’s irrevocably mine. There is no overarching authority that can say “no, let’s back up on that transaction, and say it never happened”. This is also pitched as an advantage, although many Bit Coin owners have been quite upset to find that their hugely-valuable piles of Bit Coins are now in someone else’s ownership.

Now, explain your tweet.

With the above perspective in the back of my head, I read the Project Bletchley report.

I even looked at the pictures.

I still didn’t really understand it, but something went “ping” in my head.

Maybe this is how C-level executives feel.

Here’s my thought:

Businesses get data from customers, users, partners, competitors, outright theft and shenanigans.

Maybe in environments where privacy is respected, like the EU, blockchains could be an avenue by which regulators enforce companies describing and PROVING where their data comes from, and that it was not acquired or used in an inappropriate manner?

When I give you my data, I sign it as coming from me, and sign that it’s now legitimately possessed by you (I won’t say “owned”, because I feel that personal data is irrevocably “owned” by the person it describes). Unlike Bit Coin, I can do this several times with the same packet of data, or different packets of data containing various other information. That information might also contain details of what I’m approving you to do with that information.

This is the start of a blockchain.

When information is transferred to a new party, that transfer will be signed, and the blockchain can be verified at that point. Further usage restrictions can be added.

Finally, when an information commissioner wants to check whether a company is handling data appropriately, they can ask for the blockchains associated with data that has been used in various ways. That then allows the commissioner to verify whether reported use or abuse has been legitimately approved or not.

And before this sounds like too much regulatory intervention, it also allows businesses to verify the provenance of the data they have, and to determine where sensitive data resides in their systems, because if it always travels with its blockchain, it’s always possible to find and trace it.

[Of course, if it travels without its blockchain, then it just looks like you either have old outdated software which doesn’t understand the blockchain and needs to be retired, or you’re doing something underhanded and inappropriate with customers’ data.]

It even allows the revocation of a set of data to be performed – when a customer moves to another provider, for instance.

Yes, there’s the downside of hugely increased storage requirements. Oh well.

Oh, and that revocation request on behalf of the customer, that would then be signed by the business to acknowledge it had been received, and would be passed on to partners – another blockchain.

So, maybe I’ve misunderstood, and this isn’t how it’s going to be used, but I think it’s an intriguing thought, and would love to hear your comments.

Untrusting the Blue Coat Intermediate CA from Windows

So, there was this tweet that got passed around the security community pretty quickly:

Kind of confusing and scary if you’re not quite sure what this all means – perhaps clear and scary if you do.

BlueCoat manufactures “man in the middle” devices – sometimes used by enterprises to scan and inspect / block outbound traffic across their network, and apparently also used by governments to scan and inspect traffic across the network.

The first use is somewhat acceptable (enterprises can prevent their users from distributing viruses or engaging in illicit behaviour from work computers, which the enterprises quite rightly believe they own and should control), but the second use is generally not acceptable, depending on how much you trust your local government.

Filippo helpfully gives instructions on blocking this from OSX, and a few people in the Twitter conversation have asked how to do this on Windows.

Disclaimer!

Don’t do this on a machine you don’t own or manage – you may very well be interfering with legitimate interference in your network traffic. If you’re at work, your employer owns your computer, and may intercept, read and modify your network traffic, subject to local laws, because it’s their network and their computer. If your government has ruled that they have the same rights to intercept Internet traffic throughout your country, you may want to consider whether your government shouldn’t be busy doing other things like picking up litter and contributing to world peace.

The simple Windows way

As with most things on Windows, there’s multiple ways to do this. Here’s one, which can be followed either by regular users or administrators. It’s several steps, but it’s a logical progression, and will work for everyone.

Step 1. Download the certificate. Really, literally, follow the link to the certificate and click “Open”. It’ll pop up as follows:

5-26-2016 3-49-29 PM

Step 2. Install the certificate. Really, literally, click the button that says “Install Certificate…”. You’ll see this prompt asking you where to save it:

5-26-2016 3-49-41 PM

Step 3. If you’re a non-administrator, and just want to untrust this certificate for yourself, leave the Store Location set to “Current User”. If you want to set this for the machine as a whole, and you’re an administrator, select Local Machine, like this:

5-26-2016 3-49-50 PM

Step 4: Click Next, to be asked where you’re putting the certificate:

5-26-2016 3-50-02 PM

Step 5: Select “Place all certificates in the following store”:

5-26-2016 3-50-16 PM

Step 6: Click the “Browse…” button to be given choices of where to place this certificate:

5-26-2016 3-50-23 PM

Step 7: Don’t select “Personal”, because that will explicitly trust the certificate. Scroll down and you’ll see “Untrusted Certificates”. Select that and hit OK:

5-26-2016 3-50-35 PM

Step 8: You’re shown the store you plan to install into:

5-26-2016 3-50-47 PM

Step 9: Click “Next” – and you’ll get a final confirmation option. Read the screen and make sure you really want to do what’s being offered – it’s reversible, but check that you didn’t accidentally install the certificate somewhere wrong. The only place this certificate should go to become untrusted is in the Untrusted Certificates store:

5-26-2016 3-50-52 PM

Step 10: Once you’re sure you have it right, click “Finish”. You’ll be congratulated with this prompt:

5-26-2016 3-50-59 PM

Step 11: Verification. Hit OK on the “import was successful” box. If you still have the Certificate open, close it. Now reopen it, from the link or from the certificate store, or if you downloaded the certificate, from there. It’ll look like this:

5-26-2016 3-51-44 PM

The certificate hasn’t actually been revoked, and you can open up the Untrusted Certificates store to remove this certificate so it’s trusted again if you find any difficulties.

Other methods

There are other methods to do this – if you’re a regular admin user on Windows, I’ll tell you the quicker way is to open MMC.EXE, add the Certificates Snap-in, select to manage either the Local Computer or Current User, navigate to the Untrusted Certificates store and Import the certificate there. For wide scale deployment, there are group policy ways to do this, too.

OK, OK, because you asked, here’s a picture of how to do it by GPO:

5-26-2016 4-49-38 PM

How do you encrypt a password?

I hate when people ask me this question, because I inevitably respond with a half-dozen questions of my own, which makes me seem like a bit of an arse.

To reduce that feeling, because the questions don’t seem to be going away any time soon, I thought I’d write some thoughts out.

Put enough locks on a thing, it's secure. Or it collapses under the weight of the locks.

Do you want those passwords in the first place?

Passwords are important objects – and because people naturally share IDs and passwords across multiple services, your holding on to a customer’s / user’s password means you are a necessary part of that user’s web of credential storage.

It will be a monumental news story when your password database gets disclosed or leaked, and even more of a story if you’ve chosen a bad way of protecting that data. You will lose customers and you will lose business; you may even lose your whole business.

Take a long hard look at what you’re doing, and whether you actually need to be in charge of that kind of risk.

Do you need those passwords to verify a user or to impersonate them?

If you are going to verify a user, you don’t need encrypted passwords, you need hashed passwords. And those hashes must be salted. And the salt must be large and random. I’ll explain why some other time, but you should be able to find much documentation on this topic on the Internet. Specifically, you don’t need to be able to decrypt the password from storage, you need to be able to recognise it when you are given it again. Better still, use an acknowledged good password hashing mechanism like PBKDF2. (Note, from the “2” that it may be necessary to update this if my advice is more than a few months old)

Now, do not read the rest of this section – skip to the next question.

Seriously, what are you doing reading this bit? Go to the heading with the next question. You don’t need to read the next bit.

<sigh/>

OK, if you are determined that you will have to impersonate a user (or a service account), you might actually need to store the password in a decryptable form.

First make sure you absolutely need to do this, because there are many other ways to impersonate an incoming user using delegation, etc, which don’t require you storing the password.

Explore delegation first.

Finally, if you really have to store the password in an encrypted form, you have to do it incredibly securely. Make sure the key is stored separately from the encrypted passwords, and don’t let your encryption be brute-forcible. A BAD way to encrypt would be to simply encrypt the password using your public key – sure, this means only you can decrypt it, but it means anyone can brute-force an encryption and compare it against the ciphertext.

A GOOD way to encrypt the password is to add some entropy and padding to it (so I can’t tell how long the password was, and I can’t tell if two users have the same password), and then encrypt it.

Password storage mechanisms such as keychains or password vaults will do this for you.

If you don’t have keychains or password vaults, you can encrypt using a function like Windows’ CryptProtectData, or its .NET equivalent, System.Security.Cryptography.ProtectedData.

[Caveat: CryptProtectData and ProtectedData use DPAPI, which requires careful management if you want it to work across multiple hosts. Read the API and test before deploying.]

[Keychains and password vaults often have the same sort of issue with moving the encrypted password from one machine to another.]

For .NET documentation on password vaults in Windows 8 and beyond, see: Windows.Security.Credentials.PasswordVault

For non-.NET on Windows from XP and later, see: CredWrite

For Apple, see documentation on Keychains

Can you choose how strong those passwords must be?

If you’re protecting data in a business, you can probably tell users how strong their passwords must be. Look for measures that correlate strongly with entropy – how long is the password, does it use characters from a wide range (or is it just the letter ‘a’ repeated over and over?), is it similar to any of the most common passwords, does it contain information that is obvious, such as the user’s ID, or the name of this site?

Maybe you can reward customers for longer passwords – even something as simple as a “strong account award” sticker on their profile page can induce good behaviour.

Length is mathematically more important to password entropy than the range of characters. An eight character password chosen from 64 characters (less than three hundred trillion combinations – a number with 4 commas) is weaker than a 64 character password chosen from eight characters (a number of combinations with 19 commas in it).

An 8-character password taken from 64 possible characters is actually as strong as a password only twice as long and chosen from 8 characters – this means something like a complex password at 8 characters in length is as strong as the names of the notes in a couple of bars of your favourite tune.

Allowing users to use password safes of their own makes it easier for them to use longer and more complex passwords. This means allowing copy and paste into password fields, and where possible, integrating with any OS-standard password management schemes

What happens when a user forgets their password?

Everything seems to default to sending a password reset email. This means your users’ email address is equivalent to their credential. Is that strength of association truly warranted?

In the process to change my email address, you should ask me for my password first, or similarly strongly identify me.

What happens when I stop paying my ISP, and they give my email address to a new user? Will they have my account on your site now, too?

Every so often, maybe you should renew the relationship between account and email address – baselining – to ensure that the address still exists and still belongs to the right user.

Do you allow password hints or secret questions?

Password hints push you dangerously into the realm of actually storing passwords. Those password hints must be encrypted as well as if they were the password themselves. This is because people use hints such as “The password is ‘Oompaloompah’” – so, if storing password hints, you must encrypt them as strongly as if you were encrypting the password itself. Because, much of the time, you are. And see the previous rule, which says you want to avoid doing that if at all possible.

Other questions that I’m not answering today…

How do you enforce occasional password changes, and why?

What happens when a user changes their password?

What happens when your password database is leaked?

What happens when you need to change hash algorithm?

On Widespread XSS in Ad Networks

Randy Westergren posted a really great piece entitled “Widespread XSS Vulnerabilities in Ad Network Code Affecting Top Tier Publishers, Retailers

Go read it – I’ll wait.

The article triggered a lot of thoughts that I’ll enumerate here:

This is not a new thing – and that’s bad

This was reported by SoftPedia as a “new attack”, but it’s really an old attack. This is just another way to execute DOM-based XSS.

That means that web sites are being attacked by old bugs, not because their own coding is bad, but because they choose to make money from advertising.

And because the advertising industry is just waaaay behind on securing their code, despite being effectively a widely-used framework across the web.

You’ve seen previously on my blog how I attacked Troy Hunt’s blog through his advertising provider, and he’s not the first, or by any means the last, “victim” of my occasional searches for flaws.

It’s often difficult to trace which ad provider is responsible for a piece of vulnerable code, and the hosting site may not realise the nature of their relationship and its impact on security. As a security researcher, it’s difficult to get traction on getting these vulnerabilities fixed.

Important note

I’m trying to get one ad provider right now to fix their code. I reported a bug to them, they pointed out it was similar to the work Randy Westergren had written up.

So they are aware of the problem.

It’s over a month later, and the sites I pointed out to them as proofs of concept are still vulnerable.

Partly, this is because I couldn’t get a reliable repro as different ad providers loaded up, but it’s been two weeks since I sent them a reliable repro – which is still working.

Reported a month ago, reliable repro two weeks ago, and still vulnerable everywhere.

[If you’re defending a site and want to figure out which ad provider is at fault, inject a “debugger” statement into the payload, to have the debugger break at the line that’s causing a problem. You may need to do this by replacing “prompt()” or “alert()” with “(function(){debugger})()” – note that it’ll only break into the debugger if you have the debugger open at the time.]

How the “#” affects the URL as a whole

Randy’s attack example uses a symbol you won’t see at all in some web sites, but which you can’t get away from in others. The “#” or “hash” symbol, also known as “number” or “hash”. [Don’t call it “pound”, please, that’s a different symbol altogether, “£”] Here’s his example:

http://nypost.com/#1'-alert(1)-'"-alert(1)-"

Different parts of the URL have different names. The “http:” part is the “protocol”, which tells the browser how to connect and what commands will likely work. “//nypost.com/” is the host part, and tells the browser where to connect to. Sometimes a port number is used – commonly, 80 or 443 – after the host name but before the terminating “/” of the host element. Anything after the host part, and before a question-mark or hash sign, is the “path” – in Randy’s example, the path is left out, indicating he wants the root page. An optional “query” part follows the path, indicated by a question mark at its start, often taking up the rest of the URL. Finally, if a “#” character is encountered, this starts the “anchor” part, which is everything from after the “#” character on to the end of the URL.

The “anchor” has a couple of purposes, one by design, and one by evolution. The designed use is to tell the browser where to place the cursor – where to scroll to. I find this really handy if I want to draw someone’s attention to a particular place in an article, rather than have them read the whole story. [It can also be used to trigger an onfocus event handler in some browsers]

The second use is for communication between components on the page, or even on other pages loaded in frames.

The anchor tag is for the browser only

I want to emphasise this – and while Randy also mentioned it, I think many web site developers need to understand this when dealing with security.

The anchor tag is not sent to the server.

The anchor tag does not appear in your server’s logs.

WAFs cannot filter the anchor tag.

If your site is being attacked through abuse of the anchor tag, you not only can’t detect it ahead of time, you can’t do basic forensic work to find out useful things such as “when did the attack start”, “what sort of things was the attacker doing”, “how many attacks happened”, etc.

[Caveat: pedants will note that when browser code acts on the contents of the anchor tag, some of that action will go back to the server. That’s not the same as finding the bare URL in your log files.]

If you have an XSS that can be triggered by code in an anchor tag, it is a “DOM-based XSS” flaw. This means that the exploit happens primarily (or only) in the user’s browser, and no filtering on the server side, or in the WAF (a traditional, but often unreliable, measure against XSS attacks), will protect you.

When trying out XSS attacks to find and fix them, you should try attacks in the anchor tag, in the query string, and in the path elements of the URL if at all possible, because they each will get parsed in different ways, and will demonstrate different bugs.

What does “-alert(1)-“ even mean?

The construction Randy uses may seem a little odd:

"-alert(1)-"'-alert(1)-'

With some experience, you can look at this and note that it’s an attempt to inject JavaScript, not HTML, into a quoted string whose injection point doesn’t properly (or at all) escape quotes. The two different quote styles will escape from quoted strings inside double quotes and single quotes alike (I like to put the number ‘2’ in the alert that is escaped by the double quotes, so I know which quote is escaped).

But why use a minus sign?

Surely it’s invalid syntax?

While JavaScript knows that “string minus void” isn’t a valid operation, in order to discover the types of the two arguments to the “minus” operator, it actually has to evaluate them. This is a usual side-effect of a dynamic language – in order to determine whether an operation is valid, its arguments have to be evaluated. Compiled languages are usually able to identify specific types at compile time, and tell you when you have an invalid operand.

So, now that we know you can use any operator in there – minus, times, plus, divide, and, or, etc – why choose the minus? Here’s my reasoning: a plus sign in a URL is converted to a space. A divide (“/”) is often a path component, and like multiplication (“*”) is part of a comment sequence in JavaScript, “//” or “/*”, an “&” is often used to separate arguments in a query string, and a “|” for “or” is possibly going to trigger different flaws such as command injection, and so is best saved for later.

Also, the minus sign is an unshifted character and quick to type.

There are so many other ways to exploit this – finishing the alert with a line-ending comment (“//” or “<–”), using “prompt” or “confirm” instead of “alert”, using JavaScript obfuscaters, etc, but this is a really good easy injection point.

Another JavaScript syntax abuse is simply to drop “</script>” in the middle of the JavaScript block and then start a new script block, or even just regular HTML. Remember that the HTML parser only hands off to the JavaScript parser once it has found a block between “<script …>” and “</script …>” tags. It doesn’t matter if the closing tag is “within” a JavaScript string, because the HTML parser doesn’t know JavaScript.

There’s no single ad provider, and they’re almost all vulnerable

Part of the challenge in repeating these attacks, demonstrating them to others, etc, is that there’s no single ad provider, even on an individual web site.

Two visits to the same web site not only bring back different adverts, but they come through different pieces of code, injected in different ways.

If you don’t capture your successful attack, it may not be possible to reproduce it.

Similarly, if you don’t capture a malicious advert, it may not be possible to prove who provided it to you. I ran into this today with a “fake BSOD” malvert, which pretended to be describing a system error, and filled as much of my screen as it could with a large “alert” dialog, which kept returning immediately, whenever it was dismissed, and which invited me to call for “tech support” to fix my system. Sadly, I wasn’t tracing my every move, so I didn’t get a chance to discover how this ad was delivered, and could only rage at the company hosting the page.

This is one reason why I support ad-blockers

Clearly, ad providers need to improve their security. Until such time as they do so, a great protection is to use an ad-blocker. This may prevent you from seeing actual content at some sites, but you have to ask yourself if that content is worth the security risk of exposing yourself to adverts.

There is a valid argument to be made that ad blockers reduce the ability of content providers to make legitimate profit from their content.

But there is also a valid argument that ad blockers protect users from insecure adverts.

Defence – protect your customers from your ads

Finally, if you’re running a web site that makes its money from ads, you need to behave proactively to prevent your users from being targeted by rogue advertisers.

I’m sure you believe that you have a strong, trusting relationship with the ad providers you have running ads on your web site.

Don’t trust them. They are not a part of your dev team. They see your customers as livestock – product. Your goals are substantially different, and that means that you shouldn’t allow them to write code that runs in your web site’s security context.

What this means is that you should always embed those advertising providers inside an iframe of their own. If they give you code to run, and tell you it’s to create the iframe in which they’ll site, put that code in an iframe you host on a domain outside your main domain. Because you don’t trust that code.

Why am I suggesting you do that? Because it’s the difference between allowing an advert attack to have limited control, and allowing it to have complete control, over your web site.

If I attack an ad in an iframe, I can modify the contents of the iframe, I can pop up a global alert, and I can send the user to a new page.

If I attack an ad – or its loading code – and it isn’t in an iframe, I can still do all that, but I can also modify the entire page, read secret cookies, insert my own cookies, interact with the user as if I am the site hosting the ad, etc.

If you won’t do it for your customers, at least defend your own page

capture20160409090703064

Here’s the front page of a major website with a short script running through an advert with a bug in it.

[I like the tag at the bottom left]

Insist on security clauses with all your ad providers

Add security clauses in to your contracts , so that you can pull an ad provider immediately a security vulnerability is reported to you, and so that the ad providers are aware that you have an interest in the security and integrity of your page and your users. Ask for information on how they enforce security, and how they expect you to securely include them in your page.

[I am not a lawyer, so please talk with someone who is!]

We didn’t even talk about malverts yet

Malverts – malicious advertising – is the term for an attacker getting an ad provider to deliver their attack code to your users, by signing up to provide an ad. Often this is done using apparent advertising copy related to current advertising campaigns, and can look incredibly legitimate. Sometimes, the attack code will be delayed, or region-specific, so an ad provider can’t easily notice it when they review the campaign for inclusion in your web page.

Got a virus you want to distribute? Why write distribution code and try to trick a few people into running it, when for a few dollars, you can get an ad provider to distribute it for you to several thousand people on a popular web site for people who have money?

Why am I so cross?

There are many reasons why Information Security hasn’t had as big an impact as it deserves. Some are external – lack of funding, lack of concern, poor management, distractions from valuable tasks, etc, etc.

But the ones we inflict on ourselves are probably the most irritating. They make me really cross.

Why cross?

OK, “cross” is an English term for “angry”, or “irate”, but as with many other English words, it’s got a few other meanings as well.

It can mean to wrong someone, or go against them – “I can’t believe you crossed Fingers MacGee”.

It can mean to make the sign of a cross – “Did you just cross your fingers?”

It can mean a pair of items, intersecting one another – “I’m drinking at the sign of the Skull and Cross-bones”.

It can mean to breed two different subspecies into a third – “What do you get if you cross a mountaineer with a mosquito? Nothing, you can’t cross a scaler and a vector.”

Or it can mean to traverse something – “I don’t care what Darth Vader says, I always cross the road here”.

Green_cross_man_take_it

It’s this last sense that InfoSec people seem obsessed about, to the extent that every other attack seems to require it as its first word.

Such a cross-patch

These are just a list of the attacks at OWASP that begin with the word “Cross”.

Yesterday I had a meeting to discuss how to address three bugs found in a scan, and I swear I spent more than half the meeting trying to ensure that the PM and the Developer in the room were both discussing the same bug. [And here, I paraphrase]

“How long will it take you to fix the Cross-Frame Scripting bug?”

“We just told you, it’s going to take a couple of days.”

“No, that was for the Cross-Site Scripting bug. I’m talking about the Cross-Frame Scripting issue.”

“Oh, that should only take a couple of days, because all we need to do is encode the contents of the field.”

“No, again, that’s the Cross-Site Scripting bug. We already discussed that.”

“I wish you’d make it clear what you’re talking about.”

Yeah, me too.

A modest proposal

The whole point of the word “Cross” as used in the descriptions of these bugs is to indicate that someone is doing something they shouldn’t – and in that respect, it’s pretty much a completely irrelevant word, because we’re already discussing attack types.

In many of these cases, the words “Cross-Site” bring absolutely nothing to the discussion, and just make things confusing. Am I crossing a site from one page to another, or am I saying this attack occurs between sites? What if there’s no other site involved, is that still a cross-site scripting attack? [Yes, but that’s an irrelevant question, and by asking it, or thinking about asking/answering it, you’ve reduced your mental processing abilities to handle the actual issue.]

Check yourself when you utter “cross” as the first word in the description of an attack, and ask if you’re communicating something of use, or just “sounding like a proper InfoSec tool”. Consider whether there’s a better term to use.

I’ve previously argued that “Cross-Site Scripting” is really a poor term for the conflation of HTML Injection and JavaScript Injection.

Cross-Frame Scripting is really Click-Jacking (and yes, that doesn’t exclude clickjacking activities done by a keyboard or other non-mouse source).

Cross-Site Request Forgery is more of a Forced Action – an attacker can guess what URL would cause an action without further user input, and can cause a user to visit that URL in a hidden manner.

Cross-Site History Manipulation is more of a browser failure to protect SOP – I’m not an expert in that field, so I’ll leave it to them to figure out a non-confusing name.

Cross-Site Tracing is just getting silly – it’s Cross-Site Scripting (excuse me, HTML Injection) using the TRACE verb instead of the GET verb. If you allow TRACE, you’ve got bigger problems than XSS.

Cross-User Defacement crosses all the way into crosstalk, requiring as it does that two users be sharing the same TCP connection with no adequate delineation between them. This isn’t really common enough to need a name that gets capitalised. It’s HTTP Response-Splitting over a shared proxy with shitty user segregation.

Even more modestly…

I don’t remotely anticipate that I’ll change the names people give to these vulnerabilities in scanning tools or in pen-test reports.

But I do hope you’ll be able to use these to stop confusion in its tracks, as I did:

“Never mind cross-whatever, let’s talk about how long it’s going to take you to address the clickjacking issue.”

In Summary

Here’s the TL;DR version of the web post:

Prevent or interrupt confusion by referring to bugs using the following non-confusing terms:

Confusing Not Confusing Much, Probably
Cross-Frame Scripting Clickjacking
Cross-Site History Manipulation [Not common enough to name]
Cross-Site Tracing TRACE is enabled
Cross-Site Request Forgery Forced User Action
Cross-Site Scripting HTML Injection
JavaScript Injection
Cross-User Defacement Crappy proxy server

Fear the browsing dead!

Browsing Dead

Ding dong, the plugin’s dead!

There’s been a lot of celebration lately from the security community about the impending death of Adobe’s Flash, or Oracle’s Java plugin technology.

You can understand this, because for years these plugins have been responsible for vulnerability on top of vulnerability. Their combination of web-facing access and native code execution means that you have maximum exposure and maximum risk concentrated in one place on the machine.

Browser manufacturers have recognised this risk in their own code, and have made great strides in improving security. Plus, you can always switch browsers if you feel one is more secure than another.

Attackers can rely on Flash and Java.

An attacker can pretty much assume that their target is running Flash from Adobe, and Java from Oracle. [Microsoft used to have a competing Java implementation, but Oracle sued it out of existence.]

Bugs in those implementations are widely published, and not widely patched, whether or not patches are available.

Users don’t upgrade applications (plugins included) as often or as willingly as they update their operating system. So, while your browser may be updated with the operating system, or automatically self-update, it’s likely most users are running a version of Java and/or Flash that’s several versions behind.

Applications never die, they just lose their support

As you can imagine, the declaration by Oracle that Java plugin support will be removed is a step forward in recognising the changing landscape of browser security, but it’s not an indication that this is an area in which security professionals can relax.

Just the opposite.

With the deprecation of plugin support comes the following:

  • Known bugs – without fixes. Ever.
  • No availability of tools to manage old versions.
  • No tools to protect vulnerable plugins.
  • Users desperately finding more baroque (and unsecurable) ways to keep their older setups together to continue to use applications which should have been replaced, but never were.

It’s not like Oracle are going to reach into every machine and uninstall / turn off plugin support. Even if they had the technical means to do so, such an act would be a completely inappropriate act.

There will be zombies

So, what we’re left with, whenever a company deprecates a product, application or framework, is a group of machines – zombies, if you will – that are operated by people who do not heed the call to cull, and which are going to remain active and vulnerable until such time as someone renders those walking-dead components finally lifeless.

If you’re managing an enterprise from a security perspective, you should follow up every deprecation announcement with a project to decide the impact and schedule the actual death and dismemberment of the component being killed off.

Then you can celebrate!

Assuming, of course, that you followed through successfully on your plan.

Until then, watch out for the zombies.

The Browsing Dead.

Artisan or Labourer?

Back when I started developing code, and that was a fairly long time ago, the vast majority of developers I interacted with had taken that job because they were excited to be working with technology, and enjoyed instructing and controlling computers to an extent that was perhaps verging on the creepy.

Much of what I read about application security strongly reflects this even today, where developers are exhorted to remember that security is an aspect of the overall quality of your work as a developer.

This is great – for those developers who care about the quality of their work. The artisans, if you like.

But who else is there?

For every artisan I meet when talking to developers, there’s about another two or three who are more like labourers.

They turn up on time, they do their daily grind, and they leave on time. Even if the time expected / demanded of them is longer than the usual eight hours a day.

By itself, this isn’t a bad thing. When you need another pair of “OK” and “Cancel” buttons, you want someone to hammer them out, not hand-craft them in bronze. When you need an API to a back-end database, you want it thin and functional, not baroque and beautiful.

Many – perhaps most – of your developers are there to do a job for pay, not because they love code.

And that’s what you interviewed them for, hired them for, and promoted them for.

It’s important to note that these guys mostly do what they are told. They are clever, and can be told to do complex things, but they are not single-mindedly interested in the software they are building, except in as much as you will reward them for delivering it.

What do you tell these guys?

If these developers will build only the software they’re told to build, what are you telling them to build?

At any stage, are you actively telling your developers that they have to adhere to security policies, or that they have to build in any kind of “security best practice”, or even to “think like an attacker” (much as I hate that phrase) – I’d rather you tell them to “think about all the ways every part of your code can fail, and work to prevent them” [“think like a defender”]?

Some of your developers will interject their own ideas of quality.

– But –

Most of your developers will only do as they have been instructed, and as their examples tell them.

How does this affect AppSec?

The first thing to note is that you won’t reach these developers just with optional training, and you might not even reach them just with mandatory training. They will turn up to mandatory training, because it is required of them, and they may turn up to optional training because they get a day’s pay for it. But all the appeals to them to take on board the information you’re giving them will fall upon deaf ears, if they return to their desks and don’t get follow-up from their managers.

Training requires management support, management enforcement, and management follow-through.

When your AppSec program makes training happen, your developers’ managers must make it clear to their developers that they are expected to take part, they are expected to learn something, and they are expected to come back and start using and demonstrating what they have learned.

Curiously enough, that’s also helpful for the artisans.

Second, don’t despair about these developers. They are useful and necessary, and as with all binary distinctions, the lines are not black and white, they are a spectrum of colours. There are developers at all stages between the “I turn up at 10, I work until 6 (as far as you know), and I do exactly what I’m told” end and the “I love this software as if it were my own child, and I want to mould it into a perfect shining paragon of perfection” end.

Don’t despair, but be realistic about who you have hired, and who you will hire as a result of your interview techniques.

Work with the developers you have, not the ones you wish you had.

Third, if you want more artisans and fewer labourers, the only way to do that is to change your hiring and promotion techniques.

Screen for quality-biased developers during the interview process. Ask them “what’s wrong with the code”, and reward them for saying “it’s not very easy to understand, the comments are awful, it uses too many complex constructs for the job it’s doing, etc”.

Reward quality where you find it. “We had feedback from one of the other developers on the team that you spent longer on this project than expected, but produced code that works flawlessly and is easy to maintain – you exceed expectations.”

Security is a subset of quality – encourage quality, and you encourage security.

Labourers as opposed to artisans have no internal “quality itch” to scratch, which means quality bars must be externally imposed, measured, and enforced.

What are you doing to reward developers for securing their development?