Security researcher Atte Kettunen used the Address Sanitizer tool to discover a crash while drawing images through the Cairo graphics library while using the DrawTarget function. This can result in a segmentation fault due to zero-ing out of memory outside the bounds of the image. External Reference: https://www.mozilla.org/en-US/security/advisories/mfsa2015-22 Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Atte Kettunen as the original reporter. Statement: This issue does not affect the version of firefox and thunderbird as shipped with Red Hat Enterprise Linux 5, 6 and 7.