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 adds 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. (CVE-2009-3979, CVE-2009-3981, CVE-2009-3986)
 
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. (CVE-2009-3983)
 
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. (CVE-2009-3984)
 
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. (CVE-2009-3985)
