Vulnerability Note VU#808216

Mozilla contains heap overflow in UTF8 conversion of hostname portion of URLs

Original Release date: 17 Sep 2004 | Last revised: 17 Sep 2004


A vulnerability in the way Mozilla and its derived programs handle certain malformed URLs could allow a remote attacker to execute arbitrary code on a vulnerable system.


A vulnerability exists in the way that some versions of the Mozilla and Firefox web browsers, and Thunderbird email client handle long URLs containing non-ASCII characters. The vulnerability results from a buffer overflow error in heap memory that occurs during UTF8 conversion of the hostname portion of the URL. This vulnerability could be exploited by a remote attacker by supplying a specially crafted URL in a web page or email message.


A remote attacker may be able to execute arbitrary code with the privileges of the user running an affected program.


Upgrade to a fixed version of the affected software

The Mozilla Project has released new versions of the affected software that include patches for this vulnerability. Please see the Systems Affected section of this document for more information.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
MozillaAffected-17 Sep 2004
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



Information about this issue was originally published by the Mozilla Project. The Mozilla Project, in turn, credits GaŽl Delalleau and Mats Palmgren with independent discoveries of this issue.

This document was written by Chad R Dougherty.

Other Information

  • CVE IDs: Unknown
  • Date Public: 14 Sep 2004
  • Date First Published: 17 Sep 2004
  • Date Last Updated: 17 Sep 2004
  • Severity Metric: 28.59
  • Document Revision: 7


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