CRLF injection vulnerability in FlatNuke 2.5.5 and possibly earlier versions allows remote attackers to execute arbitrary PHP commands via an ASCII char 13…

CRLF injection vulnerability in FlatNuke 2.5.5 and possibly earlier versions allows remote attackers to execute arbitrary PHP commands via an ASCII char 13 (carriage return) in the signature field, which is injected into a PHP script without a preceding comment character, which can then be executed by a direct request.