USN-186-1: Mozilla and Firefox vulnerabilities

23 September 2005

mozilla, mozilla-firefox vulnerabilities

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

  • Ubuntu 5.04
  • Ubuntu 4.10

Software Description


Peter Zelezny discovered that URLs which are passed to Firefox or Mozilla on the command line are not correctly protected against interpretation by the shell. If Firefox or Mozilla is configured as the default handler for URLs (which is the default in Ubuntu), this could be exploited to execute arbitrary code with user privileges by tricking the user into clicking on a specially crafted URL (for example, in an email or chat client). (CAN-2005-2968, MFSA-2005-59)

A buffer overflow was discovered in the XBM image handler. By tricking an user into opening a specially crafted XBM image, an attacker could exploit this to execute arbitrary code with the user’s privileges. (MFSA-2005-58)

Mats Palmgren discovered a buffer overflow in the Unicode string parser. Unicode strings that contained “zero-width non-joiner” characters caused a browser crash, which could possibly even exploited to execute arbitrary code with the user’s privileges. (MFSA-2005-58)

Georgi Guninski reported an integer overflow in the JavaScript engine. This could be exploited to run arbitrary code under some conditions. (MFSA-2005-58)

This update also fixes some less critical issues which are described at

Update instructions

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

Ubuntu 5.04
Ubuntu 4.10

To update your system, please follow these instructions: