Mozilla community member Jean-Max Reymond discovered a use-after-free vulnerability with a <canvas> element on a page. This occurs when a resize event is triggered in concert with style changes but the canvas references have been recreated in the meantime, destroying the originally referenced context. This results in an exploitable crash. Ucha Gobejishvili, working with HP's Zero Day Initiative, subsequently reported this same issue. External Reference: https://www.mozilla.org/security/announce/2015/mfsa2015-94.html Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Jean-Max Reymond and Ucha Gobejishvili as the original reporter.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 5 Via RHSA-2015:1693 https://rhn.redhat.com/errata/RHSA-2015-1693.html