Permissions, Privileges, and Access Controls
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.
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.