Mozilla Foundation Security Advisory 2016-37

Font vulnerabilities in the Graphite 2 library

March 8, 2016
Holger Fuhrmannek, Tyson Smith
Firefox, Firefox ESR, Thunderbird
Fixed in
  • Firefox 45
  • Firefox ESR 38.7
  • Thunderbird 38.7
  • Thunderbird 45


Security researcher Holger Fuhrmannek and Mozilla security engineer Tyson Smith reported a number of security vulnerabilities in the Graphite 2 library affecting version 1.3.5.

The issue reported by Holger Fuhrmannek is a mechanism to induce stack corruption with a malicious graphite font. This leads to a potentially exploitable crash when the font is loaded.

Tyson Smith used the Address Sanitizer tool in concert with a custom software fuzzer to find a series of uninitialized memory, out-of-bounds read, and out-of-bounds write errors when working with fuzzed graphite fonts.

To address these security vulnerabilities, Firefox 45 and Firefox ESR 38.7 have been updated to Graphite 2 version 1.3.6.