How to Avoid the 6 Most Common Audit FailuresIn a security audit, the burden is on you to provide the evidence that you've done the right things.
I’ve been through quite a few audits over the years, including a number of failures detailed recently by experienced auditor, Kyle Robinson of Grant Thornton. Here are six ways Robinson spells out to avoid these common audit failures.
Audit Failure #1 - Poor prioritization from the Top
A big part of a CISO’s job is to ensure alignment of the security program with the organization’s objectives. This is a two-way street: the program must be right for the organization, and the organization must feel right about the program. Security programs that are forced down the throat of the organization end up being spit back out. For a CISO, this means discovering what an organization values and then explaining cyber risks and controls in those terms. If the CISO can tie risk, and consequently the audit program, to what the organization cares about, then getting buy-in is easy.
Audit Failure #2 - Lack of Documentation
In an audit, the burden is on you to provide the evidence that you’ve done the right things. There is no presumption of innocence, and auditors rarely take you at your word. If you did not document something, then an auditor will assume you didn’t do it. Documentation shows consistency (We’ve done it this way every time.) and constancy (We’ve been doing it that way for years.). It also creates a pathway for training and automation as things are clearly spelled out as opposed to being known only to one key person (who will soon be quitting).
Luckily documentation isn’t hard to do if you write it as you go along. Start with high-level policies describing your intentions, write standards to define how things should be done, and then procedures to describe how they will be implemented.
Audit Failure #3 - Human Error Compounded by too many Manual Processes
Wherever humans are involved, mistakes and oversights will happen. It’s folly to assume otherwise. There are two simple techniques to manage this: reduced scope and defense-in-depth.
For audits, the scope is everything. If something is not in scope, the auditor will not need to look at it. For example, by leveraging the principle of least privilege you could remove administrator rights from everyone except a handful of IT professionals who absolutely need it. Then you have fewer people who need to be background checked, use strong authentication, and follow change controls. Fewer moving parts, fewer chances of failures.
Defense-in-depth means adding additional controls to back up the controls that could fail. A common audit failing is the admin not disabling a user on that user’s last day. A secondary control could be added for periodic review of users to HR records to ensure accounts match up.
Audit Failure #4 - Weak or Missing Risk Assessment
Since everything you do in security should be based on risk, a complete risk assessment is a must. But, what is a good risk assessment? Some people confuse a list of failure scenarios with a risk assessment. Stating that a DDoS attack could cripple your organization is not a risk statement, it is a statement of impact. Risk statements must include probabilities of occurrence of the threat such as: “It is highly likely in the next year that we will experience a DDoS attack that cripples our Internet services.” Conversely, the chance of a threat occurring alone is not a risk statement. Receiving lots of password guessing attacks against your SSH services is not a risk. However, if you say “there is a high likelihood of an SSH attack succeeding with an attacker gaining access to confidential data,” that is an actionable risk statement. I have discussed this in more depth in Can Your Risk Assessment Stand Up Under Scrutiny?
Audit Failure #5 - Internal Assessment too Self-Congratulatory
One of the principal tenets of security is to assume breach, which means to expect your security system to fail at some point and plan accordingly. A corollary to that concept is to assume control failure. It’s one thing to deploy a control like a new security policy or strong authentication. It’s another for it to be used properly to reduce risk and meet audit objectives. The best way to know if it is functioning properly is to test it regularly. This is where you can leverage internal auditors, external consultants, vulnerability scanners, and penetration testers. Any large system is going to have occasional lapses, so follow up and keep improving. It’s better for you to test something and find it failing than for an auditor or attacker to do the same.
Audit Failure #6 - Misunderstanding that some Audits are Ongoing
Many people assume they have a single audit once a year and that’s the only time they need to have their security program running properly. Putting aside the huge security risk this creates, you can also consider this a significant compliance risk. Even if an organization is currently subjected to only periodic point-in-time audits, there is the ever-growing likelihood that unexpected audits and assessments could suddenly spring up.
The FTC has become notorious for performing pop quizzes for U.S. organizations with potential security problems. Many business contracts and third-party agreements often contain “right to audit” clauses that allow business partners to conduct or demand independent assessments of security programs. I’ve seen contractual clauses that only give the audited organization 48 hours warning before the audit team arrives onsite with their checklists and magnifying glasses. With the prevalence of third-party security failures and regulatory guidance regarding testing them, these are only going to increase. It’s safe to assume that even if you aren’t being audited now, you will be soon.
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Raymond Pompon is a Principal Threat Researcher Evangelist with F5 labs. With over 20 years of experience in Internet security, he has worked closely with Federal law enforcement in cyber-crime investigations. He has recently written IT Security Risk Control Management: An ... View Full Bio