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 memory corruption flaw was found in the way Firefox decoded certain PNG images. An attacker could create a specially-crafted PNG image that, when opened, could cause Firefox to crash or, potentially, execute arbitrary code with the privileges of the user running Firefox. Several same-origin policy bypass flaws were found in Firefox. An attacker could create a malicious web page that, when viewed by a victim, could steal private data from a different website the victim has loaded with Firefox. A flaw was found in the way Firefox presented the location bar to a user. A malicious website could trick a user into thinking they are visiting the site reported by the location bar, when the page is actually content controlled by an attacker. A flaw was found in the way Firefox displayed the location bar when visiting a secure web page. A malicious server could use this flaw to present data that appears to originate from a secure server, even though it does not. A flaw was found in the way Firefox displayed certain malformed characters. A malicious web page could use this flaw to bypass certain string sanitization methods, allowing it to display malicious information to users. For technical details regarding these flaws, refer to the Mozilla security advisories for Firefox 3.6.7. 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 3.6.7, which corrects these issues. After installing the update, Firefox must be restarted for the changes to take effect.