STE WILLIAMS

Avast has disabled a component in its Windows anti-malware suite that posed, ironically enough, a significant security risk.

The software maker switched off the JavaScript interpreter in its toolkit after Google Project Zero’s Tavis Ormandy, and his colleagues, alerted the developer to design flaws in the code.

According to Avast, Ormandy potentially found a remote-code execution vulnerability in the software, the details of which were not publicly shared. Five days later, the Googler released a shell for poking around in Avast’s JavaScript engine for anyone interested in assessing the antivirus suite. He also revealed that if miscreants were able to exploit any holes in Avast’s JS engine on a victim’s computer, they would be able to run malware on that PC with system-admin-level privileges.

1/2-Last week, 3/4 @taviso reported a vulnerability to us in one of our emulators, which in theory could have been abused for RCE. On 3/9 he released a tool to simplify vuln. analysis in the emulator. Today, to protect our hundreds of millions of users, we disabled the emulator.

— Avast (@avast_antivirus) March 11, 2020

“Despite being highly privileged and processing untrusted input by design, it is unsandboxed and has poor mitigation coverage,” Ormandy explained earlier this week. It should be noted Ormandy did not disclose any specific bugs.

A couple days after the analysis tool was released, the vendor opted to do away with the emulator entirely. It does not believe the removal will significantly impact the suite’s ability to detect malware. The swift action was applauded by Ormandy.

Wow – Avast decided to disable their JavaScript interpreter globally!

The vulnerability report they mention wasn’t just me, it was a Project Zero collaboration with @natashenka 🔥🔥🔥

I think this is the right decision, it was a *lot* of attack surface. https://t.co/iFyry17HD0

— Tavis Ormandy (@taviso) March 11, 2020

Praise from the security community has been hard for Avast to come by lately. Earlier this week, the vendor took heat after it was revealed its AntiTrack tool contained security blunders that could have been exploited by man-in-the-middle snoopers to eavesdrop on supposedly secure website connections. ®

Sponsored:
Quit your addiction to storage

Article source: https://go.theregister.co.uk/feed/www.theregister.co.uk/2020/03/13/avast_javascript_security/