Updated firefox packages that fix multiple security issues are now available for Red Hat Enterprise Linux 5, 6, and 7. Red Hat Product Security has rated this update as having Critical security impact. Common Vulnerability Scoring System base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section. Mozilla Firefox is an open source web browser. XULRunner provides the XUL Runtime environment for Mozilla Firefox. Several flaws were found in the processing of malformed web content. A web page containing malicious content could cause Firefox to crash or, potentially, execute arbitrary code with the privileges of the user running Firefox. A flaw was found in the Alarm API, which could allow applications to schedule actions to be run in the future. A malicious web application could use this flaw to bypass the same-origin policy. This update disables SSL 3.0 support by default in Firefox. Details on how to re-enable SSL 3.0 support are available at: https://access.redhat.com/articles/1283153 Red Hat would like to thank the Mozilla project for reporting these issues. Upstream acknowledges Gary Kwong, Randell Jesup, Nils Ohlmeier, Jesse Ruderman, Max Jonas Werner, Joe Vennix, Berend-Jan Wever, Abhishek Arya, and Boris Zbarsky as the original reporters of these issues. For technical details regarding these flaws, refer to the Mozilla security advisories for Firefox 31.3.0 ESR. You can find a link to the Mozilla advisories in the References section of this erratum. All Firefox users should upgrade to these updated packages, which contain Firefox version 31.3.0 ESR, which corrects these issues. After installing the update, Firefox must be restarted for the changes to take effect.