The Curious Case Of Unpatchable Vulnerabilities

A fundamental component of most, if not all, IT security programs is the timely patching of vulnerabilities in critical systems.

Yet security experts are taking a new look at the strategy as data on breaches continues to show that very few attacks compromise systems using a vulnerability that could have been patched. In 2010, for example, only five vulnerabilities were exploited by attackers in the 381 breaches investigated by Verizon, according to the company's Data Breach Investigations Report (DBIR). Instead, most attackers exploited misconfigurations or gained credentials for otherwise secure systems.

The data suggests the focus of corporate IT on patching could cause managers to miss other important strategies to minimize risk, says Wade Baker, director of risk intelligence for Verizon.

"In general, the security industry is far more vulnerability-minded than we are threat-minded or focused on impact," he says. "Threat, vulnerability, and impact are the components of risk, but most of our time is spent on vulnerabilities."

The data from Verizon's report underscores that patching, while a necessary component of any vulnerability management program, is not sufficient. It's a meme that other security professionals have echoed, as well: Josh Corman, Akamai's director of security intelligence, has cited the research as a reason for companies to consider other strategies to reduce their vulnerabilities to attack and the impact of breaches.

The security experts are, however, not telling businesses to toss out their vulnerability management strategies and patch processes. Companies should just make sure they are balancing their priorities, Baker says. For example, if a company patches its systems once per quarter, then pushing for faster patches is less important that ensuring that patches are applied to all systems.

"Making that faster is probably not going to reduce the risk as much for you as making sure that the patch is deployed everywhere," Baker says. "The problem is not speed of patch deployment -- it's missing the patch deployment."

Companies should also pay more attention to detecting poorly configured information systems and educating developers on methods for more secure programming, says Marc Maiffret, chief technology officer for eEye, a vulnerability management firm. In a survey of the vulnerabilities that Microsoft patched in 2010, the company found that two simple changes -- blocking WebDAV connections and disabling Office file converters -- could have prevented the exploitation of 12 percent of all the software maker's vulnerabilities, including those used in major attacks.

"Simple best practice configurations around your operating system software and network architecture could have mitigated or helped mitigate the threat of Stuxnet, Aurora, and other major attacks," Maiffret says.

Maiffret takes issue with Verizon's data on patchable vulnerabilities, however. SQL injection flaws are not counted as patchable vulnerabilities, but could be discovered by a good vulnerability scanner and fixed, just not with a third-party patch in most cases, he argues.

Verizon's Baker accepts such critiques of the data, but responds that the data does show a valid trend: Attackers are avoiding the exploitation of vulnerabilities in favor of exploiting poor design flaws, abusing stolen credentials, or preying on trusting users. In addition to searching out poor configurations, IT security managers need to educate their users, reduce the attack surface area of their networks, and improve developers' secure-coding skills.

"Secure code development is equal [to], if not more important than, patching," Baker says. "Patching is just failed secure development."

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