This attack could pose a serious security threat. You should take immediate action to stop any damage or prevent further damage from happening.
This signature will detect the attempt to exploit a PHP Code Execution Vulnerability in ShoutPro.
ShoutPro is a messaging application implemented in PHP.
The application is prone to an arbitrary PHP code-execution vulnerability because it fails to properly sanitize user-supplied input. Specifically, it fails to sanitize input to the 'shout' parameter of 'shoutbox.php'. User-supplied input is written to the 'shouts.php' file; when further requests are made, the PHP interpreter executes the attacker's code.
An attacker can exploit this issue to execute arbitrary malicious PHP code in the context of the webserver process. This may help the attacker compromise the application and the underlying system; other attacks are also possible.
ShoutPro 1.5.2 is vulnerable; other versions may also be affected.