• Project: Joomla!
  • SubProject: libraries
  • Severity: High
  • Versions: 1.5.6 and all previous 1.5 releases
  • Exploit type: Brute Force
  • Reported Date: 2008-August-23
  • Fixed Date: 2008-September-9


A flaw with the random number generation exists which vastly reduces the entropy of system used random functions. This impacts system generated tokens and passwords. The fix increases entropy, and greatly reduces the chance of a generated token being guessed.

3PD Concerns

3PD extensions which use random number generation must properly seed the random numbers first (See JUserHelper::genRandomPassword() for more information on how to seed) To generate a random string, the following method is recommended: $password = JUtility::getHash( JUserHelper::genRandomPassword() );.

Affected Installs

All 1.5.x installs prior to and including 1.5.6 are affected.


Upgrade to latest Joomla! version (1.5.7 or newer).


The JSST at the Joomla! Security Centre.

Reported By: Stefan Esser