CVE-2013-1670: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 10.9% chance of exploitation in the next 30 days.

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 21.0, Firefox ESR 17.x before 17.0.6, Thunderbird before 17.0.6, and Thunderbird ESR 17.x before 17.0.6 does not prevent acquisition of chrome privileges during calls to content level constructors, which allows remote attackers to bypass certain read-only restrictions and conduct cross-site scripting (XSS) attacks via a crafted web site.

Affected products

• Mozilla Firefox: up to and including 20.0.1; version 19.0 only; version 19.0.1 only; version 19.0.2 only; version 20.0 only; version 17.0 only; …
• Mozilla Thunderbird: up to and including 17.0.5; version 17.0 only; version 17.0.1 only; version 17.0.2 only; version 17.0.3 only; version 17.0.4 only
• Mozilla Thunderbird ESR: version 17.0 only; version 17.0.1 only; version 17.0.2 only; version 17.0.3 only; version 17.0.4 only; version 17.0.5 only

Published 2013-05-16. Last modified 2026-06-16.