The remote host is missing an update to xulrunner-1.9 announced via advisory USN-811-1.

The problem can be corrected by upgrading your system to the following package versions: Ubuntu 8.04 LTS: firefox-3.0 3.0.13+nobinonly-0ubuntu0.8.04.1 xulrunner-1.9 1.9.0.13+nobinonly-0ubuntu0.8.04.1 Ubuntu 8.10: abrowser 3.0.13+nobinonly-0ubuntu0.8.10.1 firefox-3.0 3.0.13+nobinonly-0ubuntu0.8.10.1 xulrunner-1.9 1.9.0.13+nobinonly-0ubuntu0.8.10.1 Ubuntu 9.04: abrowser 3.0.13+nobinonly-0ubuntu0.9.04.1 firefox-3.0 3.0.13+nobinonly-0ubuntu0.9.04.1 xulrunner-1.9 1.9.0.13+nobinonly-0ubuntu0.9.04.1 After a standard system upgrade you need to restart Firefox and any applications that use xulrunner, such as Epiphany, to effect the necessary changes. https://secure1.securityspace.com/smysecure/catid.html?in=USN-811-1

Juan Pablo Lopez Yacubian discovered that Firefox did not properly display invalid URLs. 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. Furthermore, if the malicious website had a valid SSL certificate, Firefox would display the spoofed page as trusted.