Improper Neutralization of Special Elements used in a Command ('Command Injection')
The wfMangleFlashPolicy function in OutputHandler.php in MediaWiki before 1.19.22, 1.20.x through 1.22.x before 1.22.14, and 1.23.x before 1.23.7 allows remote attackers to conduct PHP object injection attacks via a crafted string containing <cross-domain-policy> in a PHP format request, which causes the string length to change when converting the request to <NOT-cross-domain-policy>.
CWE-77 - Command Injection
A command injection attack involves injecting an operating system command through the data input, which gets executed on the host operating system with the privileges of the victimized application. The impact of a command injection attack may range from loss of data confidentiality and integrity to unauthorized remote access to the hosting system. The attack may cause serious data breaches and system takeover.