You are here: Security Center > Mozilla Foundation Security Advisories > MFSA 2010-75

Mozilla Foundation Security Advisory 2010-75

Title: Buffer overflow while line breaking after document.write with long string
Impact: Critical
Announced: December 9, 2010
Reporter: Dirk Heinrich
Products: Firefox, Thunderbird, SeaMonkey

Fixed in: Firefox 3.6.13
  Firefox 3.5.16
  Thunderbird 3.1.7
  Thunderbird 3.0.11
  SeaMonkey 2.0.11


Dirk Heinrich reported that on Windows platforms when document.write() was called with a very long string a buffer overflow was caused in line breaking routines attempting to process the string for display. Such cases triggered an invalid read past the end of an array causing a crash which an attacker could potentially use to run arbitrary code on a victim's computer.