TippingPoint IPS Signature Evasion

Type securityvulns
Reporter Securityvulns
Modified 2007-07-12T00:00:00


======================================================================== = TippingPoint IPS Signature Evasion = = Vendor Website: = http://www.tippingpoint.com = = Affected Version: = TippingPoint IPS running TOS versions 2.1 & 2.2.0 - 2.2.4 = = Vendor Notified. 18th January 2006 = Public Disclosure. 11th July 2007 = http://security-assessment.com/files/advisories/2007-07-11_Tippingpoint_IPS_ Signature_Evasion.pdf ========================================================================

== Overview ==

During security analysis of the Tippingpoint IPS product a signature evasion vulnerability was discovered. The use of specific Unicode characters on particular web servers allows a remote user to bypass IPS detection.

== Exploitation ==

By using a hex encoded alternate Unicode character for forward slash (/) a request can be produced that will not match any IPS signature present in the TippingPoint device.

Example: http://www.test.com/scripts/cmd.exe is a known attack, and detected by a signature.

The same URI with alternate Unicode forward slash characters are not detected by the signature.

http://www.test.com/scripts%c0%afcmd.exe http://www.test.com/scripts%e0%80%afcmd.exe http://www.test.com/scripts%c1%9ccmd.exe

Web servers located behind a Tippingpoint IPS device which are capable of decoding alternate Unicode characters can be accessed, and exploited without triggering the IPS device.

== Solutions ==

Security-Assessment.com has been in contact with Tipping and a new version of the Tippingpoint IPS software has been released to address the discovered vulnerability. This issue has been addressed in various TOS releases as indicated by the affected product below. - X-Family devices, - non-X-Family device (not including 600E, 1200E, 2400E or 5000E), - non-X-Family device (including 600E, 1200E, 2400E or 5000E), http://www.3com.com/securityalert/alerts/3COM-07-003.html

== Credit ==

Discovered and advised to Tippingpoint January 18th 2006 by Paul Craig of Security-Assessment.com

== About Security-Assessment.com ==

About Security-Assessment.com Security-Assessment.com is Australasia's leading team of Information Security consultants specialising in providing high quality Information Security services to clients throughout the Asia Pacific region. Our clients include some of the largest globally recognised companies in areas such as finance, telecommunications, broadcasting, legal and government. Our aim is to provide the very best independent advice and a high level of technical expertise while creating long and lasting professional relationships with our clients.

Security-Assessment.com is committed to security research and development, and its team continues to identify and responsibly publish vulnerabilities in public and private software vendor's products. Members of the Security-Assessment.com R&D team are globally recognised through their release of whitepapers and presentations related to new security research.

Security-Assessment.com is an Endorsed Commonwealth Government of Australia supplier and sits on the Australian Government Attorney-General's Department Critical Infrastructure Project panel. We are certified by both Visa and MasterCard under their Payment Card Industry Data Security Standard Programs.

Paul Craig Security Consultant Security-Assessment.com