The remote host is missing an update to xulrunner-1.9 announced via advisory USN-873-1.

The problem can be corrected by upgrading your system to the following package versions: Ubuntu 8.04 LTS: firefox-3.0 3.0.16+nobinonly-0ubuntu0.8.04.1 xulrunner-1.9 1.9.0.16+nobinonly-0ubuntu0.8.04.1 Ubuntu 8.10: abrowser 3.0.16+nobinonly-0ubuntu0.8.10.1 firefox-3.0 3.0.16+nobinonly-0ubuntu0.8.10.1 xulrunner-1.9 1.9.0.16+nobinonly-0ubuntu0.8.10.1 Ubuntu 9.04: abrowser 3.0.16+nobinonly-0ubuntu0.9.04.1 firefox-3.0 3.0.16+nobinonly-0ubuntu0.9.04.1 xulrunner-1.9 1.9.0.16+nobinonly-0ubuntu0.9.04.1 After a standard system upgrade you need to restart Firefox and any applications that use xulrunner to effect the necessary changes. https://secure1.securityspace.com/smysecure/catid.html?in=USN-873-1

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)