Use-after-free vulnerability in the LiveConnect bridge code for Mozilla Firefox 2.x before 2.0.0.1, 1.5.x before 1.5.0.9, Thunderbird before 1.5.0.9, and SeaMonkey before 1.0.7 allows remote attackers to cause a denial of service (crash) via unknown vectors.

Certain privileged UI code in Mozilla Firefox and Thunderbird before 1.5.0.4 calls content-defined setters on an object prototype, which allows remote attackers to execute code at a higher privilege than intended.

Mozilla Firefox and Thunderbird before 1.5.0.4 associates XUL attributes with the wrong URL under certain unspecified circumstances, which might allow remote attackers to bypass restrictions by causing a persisted string to be associated with the wrong URL.

Firefox before 1.0.5, Thunderbird before 1.0.5, Mozilla before 1.7.9, Netscape 8.0.2, and K-Meleon 0.9 runs XBL scripts even when Javascript has been disabled, which makes it easier for remote attackers to bypass such protection.