Mozilla Firefox And Thunderbird Use-After-Free Vulnerability (CVE-2020-6819)
Severity: high · Patch status: patched · Since 2021-11-03 · CVE-2020-6819
Mozilla Firefox and Thunderbird contain a race condition vulnerability when running the nsDocShell destructor under certain conditions. The race condition creates a use-after-free vulnerability, causing unspecified impacts. CISA added CVE-2020-6819 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means attackers are exploiting it in the wild.
What to do
- Apply updates per vendor instructions.
- US federal agencies must remediate by May 3, 2022 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
