Integer overflow in Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, Thunderbird 3.0.x before 3.0.6 and 3.1.x before 3.1.1, and SeaMonkey before 2.0.6 allows remote attackers to execute arbitrary code via a large selection attribute in a XUL tree element, which triggers a use-after-free.

intl/uconv/util/nsUnicodeDecodeHelper.cpp in Mozilla Firefox before 3.6.7 and Thunderbird before 3.1.1 inserts a U+FFFD sequence into text in certain circumstances involving undefined positions, which might make it easier for remote attackers to conduct cross-site scripting (XSS) attacks via crafted 8-bit text.

Use-after-free vulnerability in the attribute-cloning functionality in the DOM implementation in Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, and SeaMonkey before 2.0.6, allows remote attackers to execute arbitrary code via vectors related to deletion of an event attribute node with a nonzero reference count.

Mozilla Firefox before 3.6.7 and Thunderbird before 3.1.1 do not properly implement read restrictions for CANVAS elements, which allows remote attackers to obtain sensitive cross-origin information via vectors involving reference retention and node deletion.

Buffer overflow in pngpread.c in libpng before 1.2.44 and 1.4.x before 1.4.3, as used in progressive applications, might allow remote attackers to execute arbitrary code via a PNG image that triggers an additional data row.

The nsIScriptableUnescapeHTML.parseFragment method in the ParanoidFragmentSink protection mechanism in Mozilla Firefox before 3.5.17 and 3.6.x before 3.6.14, Thunderbird before 3.1.8, and SeaMonkey before 2.0.12 does not properly sanitize HTML in a chrome document, which makes it easier for remote attackers to execute arbitrary JavaScript with chrome privileges via a javascript: URI in input to an extension, as demonstrated by a javascript:alert sequence in (1) the HREF attribute of an A element or (2) the ACTION attribute of a FORM element.

The Math.random function in the JavaScript implementation in Mozilla Firefox 3.5.x before 3.5.10 and 3.6.x before 3.6.4, and SeaMonkey before 2.0.5, uses a random number generator that is seeded only once per browser session, which makes it easier for remote attackers to track a user, or trick a user into acting upon a spoofed pop-up message, by calculating the seed value, related to a "temporary footprint" and an "in-session phishing attack."