USN-779-1: Firefox and Xulrunner vulnerabilities

12 June 2009

firefox-3.0, xulrunner-1.9 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 9.04
  • Ubuntu 8.10
  • Ubuntu 8.04 LTS

Software Description

  • firefox-3.0
  • xulrunner-1.9


Several flaws were discovered 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-2009-1392, CVE-2009-1832, CVE-2009-1833, CVE-2009-1837, CVE-2009-1838)

Pavel Cvrcek discovered that Firefox would sometimes display certain invalid Unicode characters as whitespace. An attacker could exploit this to spoof the location bar, such as in a phishing attack. (CVE-2009-1834)

Gregory Fleischer, Adam Barth and Collin Jackson discovered that Firefox would allow access to local files from resources loaded via the file: protocol. If a user were tricked into downloading then opening a malicious file, an attacker could steal potentially sensitive information. (CVE-2009-1835, CVE-2009-1839)

Shuo Chen, Ziqing Mao, Yi-Min Wang, and Ming Zhang discovered that Firefox did not properly handle error responses when connecting to a proxy server. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information. (CVE-2009-1836)

Wladimir Palant discovered Firefox did not check content-loading policies when loading external script files into XUL documents. As a result, Firefox might load malicious content under certain circumstances. (CVE-2009-1840)

It was discovered that Firefox could be made to run scripts with elevated privileges. If a user were tricked into viewing a malicious website, an attacker could cause a chrome privileged object, such as the browser sidebar, to run arbitrary code via interactions with the attacker controlled website. (CVE-2009-1841)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 9.04
abrowser - 3.0.11+build2+nobinonly-0ubuntu0.9.04.1
firefox-3.0 - 3.0.11+build2+nobinonly-0ubuntu0.9.04.1
xulrunner-1.9 -
Ubuntu 8.10
abrowser - 3.0.11+build2+nobinonly-0ubuntu0.8.10.1
firefox-3.0 - 3.0.11+build2+nobinonly-0ubuntu0.8.10.1
xulrunner-1.9 -
Ubuntu 8.04 LTS
firefox-3.0 - 3.0.11+build2+nobinonly-0ubuntu0.8.04.1
xulrunner-1.9 -

To update your system, please follow these instructions:

After a standard system upgrade you need to restart Firefox and any applications that use xulrunner, such as Epiphany, to effect the necessary changes.