Audit Insanity

<RANT>

It’s amazing, but the deeper I dive into security, the more garbage security theater I uncover. Sure, there’s insanity everywhere, but I didn’t expect to come across some of this craziness…

One of the most recent activities I’ve been party to has been the response to an independent audit. When I inquired as to the reasoning behind the audit, the answer I’ve received has been that this is a recommended yearly activity. It’s possible that this information is incorrect, but I suspect that it’s truer than I’d like to believe.

Security audits like this are standard practice all over the US and possibly the world. Businesses are led to believe that getting audited is a good thing and that they should be repeated often. My main gripe here is that while audits can be good, they need to be done for the right reasons, not just because someone tells you they’re needed. Or, even better, the audits that are forced on a company by their insurance company, or their payment processor. These sorts of audits are there to pass the blame if something bad happens.

Let’s look a little deeper. The audit I participated in was a typical security audit. An auditor contacts you with a spreadsheet full of questions for you to answer. You will, of course, answer them truthfully. Questions included inquiries about the password policy, how security policies are distributed, and how logins are handled. They delve into areas such as logging, application timeouts, IDS/IPS use, and more. It’s fairly in-depth, but ultimately just a checklist. The auditor goes through their list, interpreting your answers, and applying checkmarks where appropriate. The auditor then generates a list of items you “failed” to comply with and you have a chance to respond. This is all incorporated into a final report which is presented to whoever requested the audit.

Some audits will include a scanning piece as well. The one I’m most familiar with in this aspect is the SecurityMetrics PCI scan. Basically, you fill out a simplified yes/no questionnaire about your security and then they run a Nessus scan against whatever IP(s) you provide to them. It’s a completely brain-dead scan, too. Here’s a perfect example. I worked for a company who processed credit cards. The system they used to do this was on a private network using outbound NAT. There were both IDS and firewall systems in place. For the size of the business and the frequency of credit card transactions, this was considerable security. But, because there was a payment card processor in the mix, they were required to perform a quarterly PCI scan. The vendor of choice, SecurityMetrics.

So, the security vendor went through their checklist and requested the IP of the server. I explained that it was behind a one-way NAT and inaccessible from the outside world. They wanted the IP of the machine, which I provided to them. 10.10.10.1. Did I mention that the host in question was behind a NAT? These “security professionals” then loaded that IP into their automated scanning system. And it failed to contact the host. Go figure. Again, we went around and around until they finally said that they needed the IP of the device doing the NAT. I explained that this was a router and wouldn’t provide them with any relevant information. The answer? We don’t care, we just need something to scan. So, they scanned a router. For years. Hell, they could still be doing it for all I know. Like I said, brain dead security.

What’s wrong with a checklist, though? The problem is, it’s a list of “common” security practices not tailored to any specific company. So, for instance, the audit may require that a company uses hardware-based authentication devices in addition to standard passwords. The problem here is that this doesn’t account for non-hardware solutions. The premise here is that two-factor authentication is more secure than just a username and password. Sure, I whole-heartedly agree. But, I would argue that public key authentication provides similar security. It satisfies the “What You Have” and “What You Know” portions of two-factor authentication. But it’s not hardware! Fine, put your key on a USB stick. (No, really, don’t. That’s not very secure.)

Other examples include the standard “Password Policy” crap that I’ve been hearing for years. Basically, you should expire passwords every 90 days or so, passwords should be “strong”, and you should prevent password reuse by remembering a history of passwords. So let’s look at this a bit. Forcing password changes every 90 days results in bad password habits. The reasoning is quite simple, and there have been studies that show this. This paper (pdf) from the University of North Carolina is a good example. Another decent write up is this article from Cryptosmith. Allow me to summarize. Forcing password expiration results in people making simpler passwords, writing passwords down, or using simplistic algorithms to generate “complex” passwords. In short, cracking these “fresh” passwords is often easier than well thought out ones.

The so-called “strong” password problem can be summarized by a rather clever XKCD comic. The long and short here is that truly complex passwords that cannot be easily cracked are either horribly complex mishmashes of numbers, letters, and symbols, or they’re long strings of generic words. Seriously, “correct horse battery staple” is significantly stronger than using a completely random 11 digit string.

And, of course, password history. This sort of goes hand-in-hand with password expiration, but not always. If it’s used in conjunction with password expiration, then it generally results in single character variation in passwords. Your super-secure “complex” password of “Password1” (seriously, it meets the criteria.. Uppercase, lowercase, number) becomes a series of passwords where the 1 is changed to a 2, then 3, then 4, etc. until the history is exceeded and the user can return to 1 again. It’s easier to remember that way and the user doesn’t have to do much extra work.

So even the standard security practices on the checklist can be questioned. The real answer here is to tweak each audit to the needs of the requestor of the audit, and to properly evaluate the responses based on the security posture of the responder. There do need to be baselines, but they should be sane baselines. If you don’t get all of the checkmarks on an audit, it may not mean you’re not secure, it may just mean you’re securing your network in a way the auditor didn’t think of. There’s more to security than fancy passwords and firewalls. A lot more.

</RANT>

One thought on “Audit Insanity”

  1. Ouch, I had to sit up and actually give a moan when I saw the firm you had an audit from. Stories like yours are not new, and all illustrate the incompetence of securitymetrics.com.

    Password security is such a touchy subject, because there’s no actual correct answer. For instance, if I let an employee go today, what assurance do I have that they don’t take an account/password pair with them when they leave?

    If that password never expires or allows historical reuse, that pilfered account may be useful indefinitely. With password expirations and historical memory, I can at least be reasonably sure that in 60 days, all accounts are now changed.

    It’s unfortunate that needing a new password that is different from the last 20 results in just changing the trailing character for so many people, but changing the trailing character is better than not changing it ever.

    Password cracking is also a topic that depends entirely on the assumptions made in a scenario. For instance, an 11 character mixed random password will be cracked before that 28 character phrase if an attacker leverages full character set generation at them both.

    But what if the attacker knows certain things like there is no mixed-case requirements or digit requirements? That can significantly change the cracking time.

    That’s not me saying that phrase is bad, it’s actually pretty darn good when the attacker has no information. Just me illustrating a point that it’s a nuanced topic that can be argued in 5 different directions.

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