The cert_TestHostName function in Mozilla before 1.7, Firefox before 0.9, and Thunderbird before 0.7, only checks the hostname portion of a certificate when the hostname portion of the URI is not a fully qualified domain name (FQDN), which allows remote attackers to spoof trusted certificates.

Mozilla (Suite) before 1.7.1, Firefox before 0.9.2, and Thunderbird before 0.7.2 allow remote attackers to launch arbitrary programs via a URI referencing the shell: protocol.

Mozilla before 1.4.2 executes Javascript events in the context of a new page while it is being loaded, allowing it to interact with the previous page (zombie document) and enable cross-domain and cross-site scripting (XSS) attacks, as demonstrated using onmousemove events.

The Script.prototype.freeze/thaw functionality in Mozilla 1.4 and earlier allows attackers to execute native methods by modifying the string used as input to the script.thaw JavaScript function, which is then deserialized and executed.

Mozilla 0.9.6 and earlier and Netscape 6.2 and earlier allows remote attackers to steal cookies from another domain via a link with a hex-encoded null character (%00) followed by the target domain.

Heap-based buffer overflow in Netscape 6.2.3 and Mozilla 1.0 and earlier allows remote attackers to crash client browsers and execute arbitrary code via a PNG image with large width and height values and an 8-bit or 16-bit alpha channel.

The POP3 mail client in Mozilla 1.0 and earlier, and Netscape Communicator 4.7 and earlier, allows remote attackers to cause a denial of service (no new mail) via a mail message containing a dot (.) at a newline, which is interpreted as the end of the message.

Mozilla 1.1 and earlier, and Mozilla-based browsers such as Netscape and Galeon, set the document referrer too quickly in certain situations when a new page is being loaded, which allows web pages to determine the next page that is being visited, including manually entered URLs, using the onunload handler.