Mozilla has released update 3.5.4 of Firefox which address various issues. This includes critical issues including crashes due to memory corruption, heap overflows due to string number conversions, crash due to web-work recursive calls and form history vulnerability.
MFSA 2009-64 Crashes with evidence of memory corruption (rv:1.9.1.4/ 1.9.0.15)
MFSA 2009-63 Upgrade media libraries to fix memory safety bugs
MFSA 2009-62 Download filename spoofing with RTL override
MFSA 2009-61 Cross-origin data theft through document.getSelection()
MFSA 2009-59 Heap buffer overflow in string to number conversion
MFSA 2009-57 Chrome privilege escalation in XPCVariant::VariantDataToJS()
MFSA 2009-56 Heap buffer overflow in GIF color map parser
MFSA 2009-55 Crash in proxy auto-configuration regexp parsing
MFSA 2009-54 Crash with recursive web-worker calls
MFSA 2009-53 Local downloaded file tampering
MFSA 2009-52 Form history vulnerable to stealing
Users should perform the update by selecting check for updates under the help menu. Macintosh administrators should mark this update as critical and perform it during their next update cycle via Apple Remote Desktop.
drStrangeP0rk
This update addresses the memory reallocation regarding handling changes to the color map in multi image GIF files. This exploitation could lead to an attacker executing code with the privileges of the users permissions.
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=830