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. TippingPoint IPS running TOS versions 2.1 and 2.2.0 through 2.2.4 are affected.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/57623/tipping-bypass.txt
Source: https://packetstormsecurity.com/files/57623/tipping-bypass.txt.html