Joomla! before 1.0.11 does not properly unset variables when the input data includes a numeric parameter with a value matching an alphanumeric parameter's hash value, which allows remote attackers to have an unspecified impact. NOTE: it could be argued that this vulnerability is due to a bug in the unset PHP command (CVE-2006-3017) and the proper fix should be in PHP; if so, then this should not be treated as a vulnerability in Joomla!.
CWE-20