Version 1.3.1 of Snort, the lightweight network intrusion detection system. Version 1.3.1 fixes an annoying crash bug, plus enhances a number of features of the program. Invalid ICMP types/codes can now be filtered or monitored, the tcpdump file playback facility can use BPF filters, and the packet payload size check keyword now accepts greater than/less than modifiers.
You can download it from the following link: https://packetstormsecurity.com/files/download/11747/snort-1.3.1.tar.gz
Source: https://packetstormsecurity.com/files/11747/snort-1.3.1.tar.gz.html