TippingPoint Intrusion Prevention System Alternate Unicode Character Encodings Lets Remote Users Evade Detection
SecurityTracker Alert ID: 1018361|
SecurityTracker URL: http://securitytracker.com/id/1018361
(Links to External Site)
Updated: May 6 2008|
Original Entry Date: Jul 11 2007
Host/resource access via network|
Fix Available: Yes Vendor Confirmed: Yes Exploit Included: Yes |
Version(s): 2.1, 2.2.0 - 2.2.4|
A vulnerability was reported in TippingPoint Intrusion Prevention System. A remote user can evade detection.|
A remote user can send specially encoded data to avoid detection by the IPS. Specific Unicode encoding for the forward slash character can be used to cause the request to fail to match IPS signatures.
Some web servers will properly decode these characters.
Some demonstration exploit URLs are provided:
The vendor was notified on January 18, 2006.
Paul Craig of Security-Assessment.com discovered this vulnerability.
The original advisory is available at:
A remote user can evade intrusion detection.|
The vendor has issued fixed versions.|
The 3Com/TippingPoint advisory is available at:
Vendor URL: www.3com.com/securityalert/alerts/3COM-07-003.html (Links to External Site)
Input validation error|
Source Message Contents
Subject: TippingPoint IPS Signature Evasion|
= TippingPoint IPS Signature Evasion
= Vendor Website:
= 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
== 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.
http://www.test.com/scripts/cmd.exe is a known attack, and detected by a
The same URI with alternate Unicode forward slash characters are not
detected by the signature.
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
This issue has been addressed in various TOS releases as indicated
by the affected product below.
- X-Family devices, 188.8.131.5282.
- non-X-Family device (not including 600E, 1200E,
2400E or 5000E), 184.108.40.20626.
- non-X-Family device (including 600E, 1200E, 2400E
or 5000E), 220.127.116.1119.
== Credit ==
Discovered and advised to Tippingpoint January 18th 2006
by Paul Craig of Security-Assessment.com
== About Security-Assessment.com ==
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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
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and a high level of technical expertise while creating long and lasting
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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
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Security-Assessment.com is an Endorsed Commonwealth Government of Australia
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