Mozilla Firefox and Thunderbird Type Confusion Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-05-23
• EPSS: 38% chance of exploitation in the next 30 days (higher than 99% of CVEs)

[ Description ]Official description

A type confusion vulnerability can occur when manipulating JavaScript objects due to issues in Array.pop. This can allow for an exploitable crash. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Firefox ESR < 60.7.1, Firefox < 67.0.3, and Thunderbird < 60.7.2.

CISA: Mozilla Firefox and Thunderbird contain a type confusion vulnerability that can occur when manipulating JavaScript objects due to issues in Array.pop, allowing for an exploitable crash.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 13 Jun 2022): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• bugzilla.mozilla.org/show_bug.cgiIssue TrackingPermissions RequiredVendor Advisory
• security.gentoo.org/glsa/201908-12Third Party Advisory
• www.mozilla.org/security/advisories/mfsa2019-18Vendor Advisory
• www.mozilla.org/security/advisories/mfsa2019-20Vendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource