Mozilla: Multiple Use-after-free issues (MFSA 2012-58)
Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 do not properly iterate through the characters in a text run, which allows remote attackers to execute arbitrary code via a crafted document.