Security researcher Alex Chapman reported that the Almost Native Graphics Layer Engine (ANGLE) library used by Mozilla is vulnerable to an integer overflow. This vulnerability is present because of insufficient bounds checking in the drawLineLoop function, which can be driven by web content to overflow allocated memory, leading to a potentially exploitable crash. In general this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled, but is potentially a risk in browser or browser-like contexts. External Reference: http://www.mozilla.org/security/announce/2013/mfsa2013-78.html Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Alex Chapman as the original reporter. Statement: This issue does not affect the version of firefox and thunderbird as shipped with Red Hat Enterprise Linux 5 and 6