Views:
Severity
Description
1—Information
Port-based traffic (examples: HTTP, SMTP).
2—Low
Policy-related signatures (examples: IM, P2P, Games)
3—Medium
Tunneling and scanning activity.
4—High
Most intrusion-related signatures.
5—Critical
Same as high severity plus very high impact to servers and end users (examples: CVE-2008-4250, Conficker).