The DecodeTCPOptions function in decode.c in Snort before 2.3.0, when printing TCP/IP options using FAST output or verbose mode, allows remote attackers to cause a denial of service (crash) via packets with invalid TCP/IP options, which trigger a null dereference.
secunia.com/advisories/13664
securitytracker.com/id?1012656
taosecurity.blogspot.com/2004/12/details-on-snort-dos-condition-you-may.html
www.frsirt.com/exploits/20041222.angelDust.c.php
www.osvdb.org/12578
www.securiteam.com/exploits/6X00L20C0S.html
www.securityfocus.com/bid/12084
www.snort.org/arc_news/
exchange.xforce.ibmcloud.com/vulnerabilities/18689