Mozilla Firefox 2.0.0.1 and earlier does not prompt users before saving bookmarklets, which allows remote attackers to bypass the same-domain policy by tricking a user into saving a bookmarklet with a data: scheme, which is executed in the context of the last visited web page.

Mozilla based browsers, including Firefox before 1.5.0.10 and 2.x before 2.0.0.2, and SeaMonkey before 1.0.8, allow remote attackers to bypass the same origin policy, steal cookies, and conduct other attacks by writing a URI with a null byte to the hostname (location.hostname) DOM property, due to interactions with DNS resolver code.

Stack-based buffer overflow in Mozilla Firefox allows remote attackers to execute arbitrary code via unspecified vectors involving JavaScript. NOTE: the vendor and original researchers have released a follow-up comment disputing the severity of this issue, in which the researcher states that "we mentioned that there was a previously known Firefox vulnerability that could result in a stack overflow ending up in remote code execution. However, the code we presented did not in fact do this... I have not succeeded in making this code do anything more than cause a crash and eat up system resources"

Multiple unspecified vulnerabilities in Mozilla Firefox have unspecified vectors and impact, as claimed during ToorCon 2006. NOTE: the vendor and original researchers have released a follow-up comment disputing this issue, in which one researcher states that "I have no undisclosed Firefox vulnerabilities. The person who was speaking with me made this claim, and I honestly have no idea if he has them or not.

Cross-domain vulnerability in Mozilla Firefox allows remote attackers to access restricted information from other domains via an object tag with a data parameter that references a link on the attacker's originating site that specifies a Location HTTP header that references the target site, which then makes that content available through the outerHTML attribute of the object. NOTE: this description was based on a report that has since been retracted by the original authors. The authors misinterpreted their test results. Other third parties also disputed the original report. Therefore, this is not a vulnerability. It is being assigned a candidate number to provide a clear indication of its status

Mozilla Firefox 1.5.0.4, 2.0.x before 2.0.0.8, Mozilla Suite 1.7.13, Mozilla SeaMonkey 1.0.2 and other versions before 1.1.5, and Netscape 8.1 and earlier allow user-assisted remote attackers to read arbitrary files by tricking a user into typing the characters of the target filename in a text box and using the OnKeyDown, OnKeyPress, and OnKeyUp Javascript keystroke events to change the focus and cause those characters to be inserted into a file upload input control, which can then upload the file when the user submits the form.

Mozilla Firefox and Thunderbird before 1.5.0.4 allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via (1) nested <option> tags in a select tag, (2) a DOMNodeRemoved mutation event, (3) "Content-implemented tree views," (4) BoxObjects, (5) the XBL implementation, (6) an iframe that attempts to remove itself, which leads to memory corruption.