-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hardened PHP Project www.hardened-php.net -= Security Advisory =- Advisory: Remote code execution in Serendipity Release Date: 2005/06/29 Last Modified: 2005/06/29 Author: Christopher Kunz Application: Serendipity <= 0.8.2 Severity: Arbitrary remote code execution Risk: Very High Vendor Status: Vendor has released an updated version References: http://www.hardened-php.net/advisory-022005.php Overview: Quote from http://www.s9y.org/: "Serendipity is a weblog/blog system, implemented with PHP. It is standards compliant, feature rich and open source (BSD License). Serendipity is constantly under active development, with a team of talented developers trying to make the best PHP powered blog on the net." Details: GulfTech Security [1] recently discovered a vulnerability in the PHP XML RPC project [2] that leads to remote code execution. Unfortunately, this vulner- ability also exists in the PEAR XMLRPC implementation, and GulfTech somewhat neglected to notify the vendors in question. Similar to the recently-discovered holes in PostNuke and Drupal, the XML-RPC parser in Serendipity allows for remote code execution. An attacker can send a forged POST request to the victim's blog and include PHP code in the request body. This code is executed in the context of the affected Serendipity instance. Since the vulnerability is extremely easy to exploit and apart from one POST request, no suspicious activity is logged, it could be used for automated mass defacements and viral reproduction, similar to Santy. The Hardened PHP project had knowledge of that kind of vulnerability for some time now but tried to establish a responsible way of coordinating the disclosure with all affected parties. The maintainer of PEAR::XML_RPC has released an updated version that fixes the vulnerability. The Serendipity team has released a fixed version, too. CVE Information: The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-1921 to the vulnerability in PEAR::XML_RPC. Proof of Concept: The Hardened PHP Project is not going to release an exploit for this vulnerability to the public. It is trivial to implement, anyway. Disclosure Timeline: 29. June 2005 - Vulnerability discovered and vendor notified 29. June 2005 - Vendor released bugfixed version 29. June 2005 - Public disclosure Recommendation: We urge you to update to the newest version of Serendipity, 0.8.2. http://prdownloads.sourceforge.net/php-blog/serendipity-0.8.2.tar.gz If, for some reason, that seems unfeasible, you should render the file serendipity_xmlrpc.php unreadable by the web server to close the most obvious attack vector. References: [ 1 ] http://www.gulftech.org/ [ 2 ] http://phpxmlrpc.sourceforge.net/ GPG-Key: http://www.hardened-php.net/hardened-php-signature-key.asc pub 1024D/0A864AA1 2004-04-17 Hardened-PHP Signature Key Key fingerprint = 066F A6D0 E57E 9936 9082 7E52 4439 14CC 0A86 4AA1 Copyright 2005 Christopher Kunz from the hardened PHP Project. All rights reserved. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQFCwtB+RDkUzAqGSqERAmh4AKDFA745A5oQWlowMAdYn9DZ5KMxZwCfayFC KiCl/YVS7QPt0hw6pLsz8QA= =pfYU -----END PGP SIGNATURE----- _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/