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 terminate unexpectedly or, potentially, execute arbitrary code with the privileges of the user running Firefox. A flaw was found in the way Firefox rendered web content with missing character encoding information. An attacker could use this flaw to possibly bypass same-origin inheritance and perform cross-site scripting attacks. It was found that certain malicious web content could bypass restrictions applied by sandboxed iframes. An attacker could combine this flaw with other vulnerabilities to execute arbitrary code with the privileges of the user running Firefox. Red Hat would like to thank the Mozilla project for reporting these issues. Upstream acknowledges Ben Turner, Bobby Holley, Jesse Ruderman, Christian Holler, Masato Kinugawa, Daniel Veditz, Jesse Schwartzentruber, Nils, Tyson Smith, and Atte Kettunen as the original reporters of these issues. For technical details regarding these flaws, refer to the Mozilla security advisories for Firefox 24.2.0 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 24.2.0 ESR, which corrects these issues. After installing the update, Firefox must be restarted for the changes to take effect.