The SMTP client in Mozilla Thunderbird 1.0.5 BETA, 1.0.7, and possibly other versions, does not notify users when it cannot establish a secure channel with the server, which allows remote attackers to obtain authentication information without detection via a man-in-the-middle (MITM) attack that bypasses TLS authentication or downgrades CRAM-MD5 authentication to plain authentication.

Mozilla Firefox 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 allows remote attackers to trick users into downloading and saving an executable file via an image that is overlaid by a transparent image link that points to the executable, which causes the executable to be saved when the user clicks the "Save image as..." option. NOTE: this attack is made easier due to a GUI truncation issue that prevents the user from seeing the malicious extension when there is extra whitespace in the filename.

Mozilla Firefox 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 allows remote attackers to spoof secure site indicators such as the locked icon by opening the trusted site in a popup window, then changing the location to a malicious site.