Mozilla Firefox before 1.5.0.7 and Thunderbird before 1.5.0.7 makes it easy for users to accept self-signed certificates for the auto-update mechanism, which might allow remote user-assisted attackers to use DNS spoofing to trick users into visiting a malicious site and accepting a malicious certificate for the Mozilla update site, which can then be used to install arbitrary code on the next update.
The popup blocker in Mozilla Firefox before 1.5.0.7 opens the "blocked popups" display in the context of the Location bar instead of the subframe from which the popup originated, which might make it easier for remote user-assisted attackers to conduct cross-site scripting (XSS) attacks.
Multiple unspecified vulnerabilities in the layout engine in Mozilla Firefox before 1.5.0.10 and 2.x before 2.0.0.2, Thunderbird before 1.5.0.10, and SeaMonkey before 1.0.8 allow remote attackers to cause a denial of service (crash) and potentially execute arbitrary code via certain vectors.