Asterisk Project Security Advisory – The HTTP Manager ID used by Asterisk is predictable, allowing an attack the ability to hijack a manager session.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/64695/AST-2008-005.txt
Source: https://packetstormsecurity.com/files/64695/AST-2008-005.txt.html