USN-873-1 fixed vulnerabilities in Firefox and Xulrunner. The upstream changes introduced a regression when using NTLM authentication. This update fixes the problem and added additional stability fixes. We apologize for the inconvenience. Original advisory details: Jesse Ruderman, Josh Soref, Martijn Wargers, Jose Angel, Olli Pettay, and David James discovered several flaws in the browser and JavaScript engines of Firefox. If a user were tricked into viewing a malicious website, a remote attacker could cause a denial of service or possibly execute arbitrary code with the privileges of the user invoking the program. Takehiro Takahashi discovered flaws in the NTLM implementation in Firefox. If an NTLM authenticated user visited a malicious website, a remote attacker could send requests to other applications, authenticated as the user. Jonathan Morgan discovered that Firefox did not properly display SSL indicators under certain circumstances. This could be used by an attacker to spoof an encrypted page, such as in a phishing attack. Jordi Chancel discovered that Firefox did not properly display invalid URLs for a blank page. If a user were tricked into accessing a malicious website, an attacker could exploit this to spoof the location bar, such as in a phishing attack