CVE-2011-2993: Mozilla Firefox

High severity, CVSS 9.3. EPSS: 1.3% chance of exploitation in the next 30 days.

The implementation of digital signatures for JAR files in Mozilla Firefox 4.x through 5, SeaMonkey 2.x before 2.3, and possibly other products does not prevent calls from unsigned JavaScript code to signed code, which allows remote attackers to bypass the Same Origin Policy and gain privileges via a crafted web site, a different vulnerability than CVE-2008-2801.

Affected products

• Mozilla Firefox: version 4.0 only; version 4.0.1 only; version 5.0 only
• Mozilla Seamonkey: version 2.0 only; version 2.0.1 only; version 2.0.2 only; version 2.0.3 only; version 2.0.4 only; version 2.0.5 only; …

Published 2011-08-18. Last modified 2026-06-16.