The weakness was disclosed 08/01/2013 by Jens Hinrichsen.
Vulnerable component: Joomla!
CVSSv3 score: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C
CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type
The vulnerability allows a remote attacker to execute arbitrary PHP code on the target system.
The weakness exists due to improper validation of file extensions by the media.php and index.php scripts. A remote attacker can create a specially crafted HTTP request, upload a malicious PHP script and execute arbitrary PHP code.
Successful exploitation of the vulnerability results in arbitrary PHP code execution on the vulnerable system.
Note: the vulnerability was being actively exploited.