OWASP Top 10 Considered Harmful
The OWASP Top 10 is frequently used in application security circles as the go-to reference for “best practice”. However, while the Top 10 approach may once have been a great way to raise the profile of application security, its time has passed. It is at best misleading and at worst outright harmful, and a more mature industry approach must be adopted to help secure the future of business applications.
When it was originally released back in 2004, the Top 10 was intended to raise awareness of application security, at a time when it did not have the attention it deserved. But fast forward eleven years and a lot has changed. The awareness agenda has been a huge success, application security is now a $2.5 billion dollar industry, and those who ignore its risks do so at their peril.
So why is the OWASP Top 10 actually a negative influence in today’s infosec landscape? Well primarily because it exists completely outside any context at all. Cross site request forgery in an online banking application would be a genuine concern, while a SQL Injection vulnerability in the application that runs on my toaster should raise a maximum of zero eyebrows — so what if someone knows how many slices I like for breakfast. By focusing on issues rather than consequences, the Top 10 brainwashes us into an unhealthy security mindset.
This is compounded by the way the list is commonly presented, stating that these ten issues are “the most critical”, when the actual guide itself says they are merely the most common. As an example the tenth most “critical” vulnerability is when applications can forward the user to a separate website, which is barely a vulnerability at all — simply a trick played on a user who may as well be fooled in a number of other ways.
The Top 10 also ignores some major potential causes of harm in business applications — workflow bypass, or “business logic manipulation”, where a user can get around restrictions that are supposed to be enforced, for example, making a trade and bypassing authorisation from the trade floor manager.
The net result is that the Top 10 educates people in exactly the opposite direction that we should be going, it emphasises cookie cutter approaches where proper consideration is required, and allows an industry to plod along with generic approaches to complex problems. But because the Top 10 is easy to consume, the AppSec industry clings to it like a crutch, struggling to walk when it should be learning to run.
It’s time OWASP officially retired the Top 10 in its current form, and started promoting security in context, to help end the crisis of context-less security that plagues many organisations today.
- Raw CVE Coverage
- Risk Rating Coverage
- Remote Check Types
- Check Publication Lead Time
- Local/Authenticated vs Remote Check Prioritisation
- Software Vendor & Package Coverage
- Headline Vulnerabilities of 2021 Coverage
- Analysis Decisions
Red teamers, security researchers, detection engineers, threat actors have to actively research type of vulnerability, location in vulnerable software and build an associated exploit.
Tenable release checks for 47.43% of the CVEs they cover in this window, and Greenbone release 32.96%.
Red teamers, security researchers, detection engineers and threat actors now have access to some of the information they were previously having to hunt themselves, speeding up potential exploit creation.
Tenable release checks for 17.12% of the CVEs they cover in this window, and Greenbone release 17.69%.
The likelihood that exploitation in the wild is going to be happening is steadily increasing.
Tenable release checks for 10.9% of the CVEs they cover in this window, and Greenbone release 20.69%.
We’re starting to lose some of the benefit of rapid, automated vulnerability detection.
Tenable release checks for 9.58% of the CVEs they cover in this window, and Greenbone release 12.43%.
Any detection released a month after the details are publicly available is decreasing in value for me.
Tenable release checks for 14.97% of the CVEs they cover over a month after the CVE details have been published, and Greenbone release 16.23%.
With this information in mind, I wanted to check what is the delay for both Tenable and Greenbone to release a detection for their scanners. The following section will focus on vulnerabilities which:
- Have CVSSv2 rating of 10
- Are exploitable over the network
- Require no user interaction
These are the ones where an attacker can point their exploit code at your vulnerable system and gain unauthorised access.
We’ve seen previously that Tenable have remote checks for 643 critical vulnerabilities, and OpenVAS have remote checks for 450 critical vulnerabilities. Tenable release remote checks for critical vulnerabilities within 1 month of the details being made public 58.4% of the time, but Greenbone release their checks within 1 month 76.8% of the time. So, even though OpenVAS has fewer checks for those critical vulnerabilities, you are more likely to get them within 1 month of the details being made public. Let’s break that down further.
In Figure 10 we can see the absolute number of remote checks released on a given day after a CVE for a critical vulnerability has been published. What you can immediately see is that both Tenable and OpenVAS release the majority of their checks on or before the CVE details are made public; Tenable have released checks for 247 CVEs, and OpenVAS have released checks for 144 CVEs. Then since 2010 Tenable have remote released checks for 147 critical CVEs and OpenVAS 79 critical CVEs on the same day as the vulnerability details were published. The number of vulnerabilities then drops off across the first week and drops further after 1 week, as we would hope for in an efficient time-to-release scenario.
While raw numbers are good, Tenable have a larger number of checks available so it could be unfair to go on raw numbers alone. It’s potentially more important to understand the likelihood that OpenVAS or Tenable will release a check of a vulnerability on any given day after a CVE for a critical vulnerability is released. In Figure 11 we can see that Tenable release 61% their checks on or before the date that a CVE is published, and OpenVAS release a shade under 50% of their checks on or before the day that a CVE is published.
So, since 2010 Tenable has more frequently released their checks before or on the same day as the CVE details have been published for critical vulnerabilities. While Tenable is leading at this point, Greenbone’s community feed still gets a considerable percentage of their checks out on or before day 0.
I thought I’d go another step further and try and see if I could identify any trend in each organisations release delay, are they getting better year-on-year or are their releases getting later? In Figure 12 I’ve taken the mean delay for critical vulnerabilities per year and plotted them. The mean as a metric is particularly influenced by outliers in a data set, so I expected some wackiness and limited the mean to only checks released 180 days prior to a CVE being published and 31 days after a CVE being published. These seem to me like reasonable limits, as anything greater than 6 months prior to CVE details being released is potentially a quirk of the check details and anything after a 1-month delay is less important for us.
What can we take away from Figure 12?
- We can see that between 2011 and 2014 Greenbone’s release delay was better than that of Tenable, by between 5 and 10 days.
- In 2015 things reverse and for 3 years Tenable is considerably ahead of Greenbone by a matter of weeks.
- But, then in 2019 things get much closer and Greenbone seem to be releasing on average about a day earlier than Tenable.
- For both the trendline over an 11-year period is very close, with Tenable marginally beating Greenbone.
- We have yet to have any data for 2021 for OpenVAS checks for critical show-stopper CVEs.
With the larger number of checks, and still being able to release a greater percentage of their remote checks for critical vulnerabilities Tenable could win this category. However, the delay time from 2019 and 2020 going to OpenVAS, and the trend lines being so close, I am going to declare this one a tie. It’s a tie.
The takeaway from this is that both vendors are getting their checks out the majority of the time either before the CVE details are published or on the day the details are published. This is overwhelmingly positive for both scanning solutions. Over time both also appear to be releasing remote checks for critical vulnerabilities more quickly.