Mozilla has revealed that a critical security flaw impacting Firefox and Firefox Extended Support Release (ESR) has come under active exploitation in the wild.
The vulnerability, tracked as CVE-2024-9680 (CVSS score: 9.8), has been described as a use-after-free bug in the Animation timeline component.
"An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines," Mozilla said in a Wednesday advisory.
"We have had reports of this vulnerability being exploited in the wild."
Security researcher Damien Schaeffer from Slovakian company ESET has been credited with discovering and reporting the vulnerability.
The issue has been addressed in the following versions of the web browser -
- Firefox 131.0.2
- Firefox ESR 128.3.1, and
- Firefox ESR 115.16.1.
There are currently no details on how the vulnerability is being exploited in real-world attacks and the identity of the threat actors behind them.
That said, such remote code execution vulnerabilities could be weaponized in several ways, either as part of a watering hole attack targeting specific websites or by means of a drive-by download campaign that tricks users into visiting bogus websites.
Users are advised to update to the latest version to stay protected against active threats.
Update
The Tor project has released an emergency update to the Tor Browser (version 13.5.7) to address CVE-2024-9680, which has come under active exploitation in the wild.
"Using this vulnerability, an attacker could take control of Tor Browser, but probably not deanonymize you in Tails," it said. "Mozilla is aware of this attack being used in the wild against Tor Browser users."
Mozilla, in a separate post on October 11, 2024, said it was sent by ESET a sample containing a "full exploit chain that allowed remote code execution on a user's computer." It also revealed that the fix was shipped within 25 hours of responsible disclosure.
