Vulnerabilities identified by researchers in more than a dozen software products, including many security solutions, can be exploited by malicious hackers to bypass exploit mitigations and compromise systems.
In late 2015, data exfiltration prevention firm enSilo reported finding serious flaws in security products from AVG, Intel Security and Kaspersky Lab. The issues, related to how the products allocated a memory page with RWX (Read, Write, Execute) permissions at a constant predictable address, made it easier for attackers to bypass protections.
The findings led to enSilo conducting an in-depth analysis of the hooking engines and injection methods used by various companies in their software products.
Hooking is a technique used to intercept the functions of operating systems and applications to monitor or change their behavior. The technique is often used by virtualization, security and performance products. In the case of security applications, hooking is typically used to monitor a system for malicious activity.
enSilo discovered that the way some vendors implemented hooking could allow malicious actors to bypass the exploit mitigations provided by the operating system and third party applications. Most of these weaknesses make it easier for attackers to exploit vulnerabilities and compromise the targeted system.
“The worst vulnerabilities would allow the attacker to stay undetected on the victim’s machine or to inject code into any process in the system,” enSilo said.
The security firm discovered a total of six different security issues affecting over 15 products, including ones from AVG, Kaspersky, Intel Security, Microsoft, Symantec, Trend Micro, Bitdefender, Citrix, Webroot, Avast, Emsisoft and Vera.
Three hooking engines have been found to be vulnerable, including Microsoft Detours, a commercial software package used by over 100 vendors. The flaw is believed to have plagued Detours since at least version 3, which means it has been around for no less than eight years.
The flaws were reported to the affected vendors over the past eight months, but enSilo said not all of them have released patches. Symantec addressed the issue in March, and Bitdefender fixed it in January, three weeks after it was reported through its bug bounty program. Avast told SecurityWeek that it resolved the bug last year, shortly after learning of its existence.
Microsoft was informed about the Detours security hole in February and the company plans on patching it next month.
Vera said it had been aware of the potential vulnerability and it moved quickly to mitigate the risk. The company said the changes have been in production for some time.
“It’s important to note that enSilo specifically recommended Microsoft Detours as the secure option to the contacted vendors, contrary to their announcement today,” Vera told SecurityWeek.
Webroot also said it had fully patched the vulnerability shortly after it learned of its existence in December 2015. The update was pushed out to all customers from the cloud immediately after its release.
enSilo will provide additional details about the vulnerabilities on August 3 at the Black Hat conference in a presentation titled “Captain Hook: Pirating AVs to Bypass Exploit Mitigations.”
*Updated with information from Webroot
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