Mandriva Linux Security Advisory 2009-259 - preprocessors/spp_frag3.c in Sourcefire Snort before 2.8.1 does not properly identify packet fragments that have dissimilar TTL values, which allows remote attackers to bypass detection rules by using a different TTL for each fragment. The updated packages have been patched to prevent this. Additionally there were problems with two rules in the snort-rules package for 2008.0 that is also fixed with this update. Packages for 2008.0 are being provided due to extended support for Corporate products.
ee5fec922445fc73e30d9ef005c7991028e684036a55c43cce10e70dfe8a3b98
Mandriva Linux Security Advisory 2009-259 - preprocessors/spp_frag3.c in Sourcefire Snort before 2.8.1 does not properly identify packet fragments that have dissimilar TTL values, which allows remote attackers to bypass detection rules by using a different TTL for each fragment. The updated packages have been patched to prevent this.
28c2075c1e4286319cc937a5d2585bf98b1ac3991c45cf7ef0e9bb1a1fa81964
iDefense Security Advisory 05.21.08 - Remote exploitation of a design error vulnerability in Snort, as included in various vendors' operating system distributions, could allow an attacker to bypass filter rules. Due to a design error vulnerability, Snort does not properly reassemble fragmented IP packets. When receiving incoming fragments, Snort checks the Time To Live (TTL) value of the fragment, and compares it to the TTL of the initial fragment. If the difference between the initial fragment and the following fragments is more than a configured amount, the fragments will be silently discard. This results in valid traffic not being examined and/or filtered by Snort. iDefense has confirmed the existence of this vulnerability in Snort 2.8 and 2.6. Snort 2.4 is not vulnerable.
71694e299caa136a88ff4553f89f1078e330d6913b0b76957abb0e2e9cfa6bff