Snort before 2.8.5.1, when the -v option is enabled, allows remote attackers to cause a denial of service (application crash) via a crafted IPv6 packet that uses the (1) TCP or (2) ICMP protocol.

preprocessors/sppfrag3.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.

Snort 1.6, when running in straight ASCII packet logging mode or IDS mode with straight decoded ASCII packet logging selected, allows remote attackers to cause a denial of service (crash) by sending non-IP protocols that Snort does not know about, as demonstrated by an nmap protocol scan.