Louhi Networks Oy -= Security Advisory =- Advisory: Buffalo AirStation WHR-G54S Web Management CSRF vulnerability Release Date: 2007-09-07 Last Modified: 2007-09-07 Authors: Henri Lindberg, Associate of (ISC)² [henri d0t lindberg at louhi d0t fi] Application: Buffalo AirStation Web Management Devices: WHR-G54S Ver.1.20, possibly other Buffalo products Severity: Cross site request forgery in management interface Risk: Moderate Vendor Status: No response from vendor. References: http://www.louhinetworks.fi/advisory/buffalo_070907.txt Overview: During cursory inspection of WHR-G54S it was discovered that a cross site request forgery vulnerability exists in the management interface. Thus, it is possible for an attacker to perform any administrative action in the management interface. These include e.g. changing administrative password or adding new firewall rules. Details: Buffalo AirStation WHR-G54S Ver.1.20 device management interface does not validate the origin of an HTTP request. If attacker is able to make user visit a hostile web page, a device can be controlled by submitting suitable forms. It is possible to add new users for example. Successful attack requires that the attacker knows the management interface address for the target device. As authentication is done using HTTP Basic authentication, exploiting this vulnerability requires more effort compared to forms authentication. Proof of Concept:Note: ropass value is reversed edit_ropass value. 220.127.116.11 = attacker's IP address Workaround: Do not browse untrusted websites while using the management interface. Log out after administering the device. More information: http://en.wikipedia.org/wiki/Cross-site_request_forgery Disclosure Timeline: XX July 2007 - Discovered the issue 15. August 2007 - Contacted Buffalo 17. August 2007 - Contacted Buffalo again. 7. September 2007 - No response from Vendor. 7. September 2007 - Advisory released Copyright 2007 Louhi Networks Oy. All rights reserved.