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.

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.

The WYSIWYG rendering engine ("rich mail" editor) in Mozilla Thunderbird 1.0.7 and earlier allows user-assisted attackers to bypass javascript security settings and obtain sensitive information or cause a crash via an e-mail containing a javascript URI in the SRC attribute of an IFRAME tag, which is executed when the user edits the e-mail.

Mozilla Firefox before 1.5.0.1, Thunderbird 1.5 if running Javascript in mail, and SeaMonkey before 1.0 allow remote attackers to execute arbitrary code by changing an element's style from position:relative to position:static, which causes Gecko to operate on freed memory.

Mozilla Firefox 1.0.1 and possibly other versions, including Mozilla and Thunderbird, allows remote attackers to spoof the URL in the Status Bar via an A HREF tag that contains a TABLE tag that contains another A tag.

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.

String handling functions in Mozilla 1.7.3, Firefox 1.0, and Thunderbird before 1.0.2, such as the nsTSubstring_CharT::Replace function, do not properly check the return values of other functions that resize the string, which allows remote attackers to cause a denial of service and possibly execute arbitrary code by forcing an out-of-memory state that causes a reallocation to fail and return a pointer to a fixed address, which leads to heap corruption.

The installation confirmation dialog in Firefox before 1.0.1, Thunderbird before 1.0.1, and Mozilla before 1.7.6 allows remote attackers to use InstallTrigger to spoof the hostname of the host performing the installation via a long "user:pass" sequence in the URL, which appears before the real hostname.

Heap-based buffer overflow in GIF2.cpp in Firefox before 1.0.2, Mozilla before to 1.7.6, and Thunderbird before 1.0.2, and possibly other applications that use the same library, allows remote attackers to execute arbitrary code via a GIF image with a crafted Netscape extension 2 block and buffer size.

Firefox 0.9, Thunderbird 0.6 and other versions before 0.9, and Mozilla 1.7 before 1.7.5 save temporary files with world-readable permissions, which allows local users to read certain web content or attachments that belong to other users, e.g. content that is managed by helper applications such as PDF.