[HACKATTACK Advisory #3]Social Impress CMS 1.1 - Session Fixation Details ************************ Product: Impress CMS Security-Risk: moderated Remote-Exploit: yes Vendor-URL: http://www.impresscms.info Vendor-Status: informed Advisory-Status: not yet published Credits ************************ Discovered by: David Vieira-Kurz http://www.HACKATTACK.at || http://www.HACKATTACK.eu Affected Products: ---------------------------- Impress CMS 1.1 and prior Original Advisory: ************************ http://www.HACKATTACK.at/ Introduction ************************ SocialEngine is a PHP-based Content Management System. More Details ************************ 1. Cookie_Manipulation: --------------------- The cookie variable "PHPSESSID" parameter can be set to a malicious and arbitrary value. 1.1 Description: In a session fixation attack, the attacker fixes the user's session ID before the user even logs into the target server. After a user's session ID has been fixed, the attacker will wait for them to login. Once the user does so, the attacker uses the predefined session ID value to assume their online identity. Workaround: ************************ 1. Do not accept session identifiers from GET / POST variables. 2.Regenerate SID on each request. 3. Accept only server generated SID: One way to improve security is to not accept session identifiers not generated by server. if ( ! isset( $_SESSION['SERVER_GENERATED_SID'] ) ) { session_destroy(); // destroy all data in session } session_regenerate_id(); // generate a new session identifier $_SESSION['SERVER_GENERATED_SID'] = true; About HACKATTACK ================ HACKATTACK IT SECURITY GmbH is a Penetrationtest and security Auditinf company located in Austria and Germany. Hotline Germany +49 (0)800 20 60 900 Hotline Austria +43 (0)06223 20 6210 More Information about HACKATTACK at http://www.HACKATTACK.at || http://www.HACKATTACK.eu