Snort is an open source network intrusion prevention system, capable of performing real-time traffic analysis and packet logging on IP networks.
It can perform protocol analysis, content searching/matching and can be used to detect a variety of attacks and probes, such as buffer overflows, stealth port scans, CGI attacks, SMB probes, OS fingerprinting attempts, and much more.
Snort 2.9.0 introduces:
- Feature rich IPS mode including improvements to Stream for inline deployments. Additionally a common active response API is used for all packet responses, including those from Stream, Respond, or React. A new response module, respond3, supports the syntax of both resp & resp2, including strafing for passive deployments. When Snort is deployed inline, a new preprocessor has been added to handle packet normalization to allow Snort to interpret a packet the same way as the receiving host.
- Use of a Data Acquisition API (DAQ) that supports many different packet access methods including libpcap, netfilterq, IPFW, and afpacket. For libpcap, version 1.0 or higher is now required. The DAQ library can be updated independently from Snort and is a separate module that Snort links.
- Updates to HTTP Inspect to extract and log IP addresses from X-Forward-For and True-Client-IP header fields when Snort generates events on HTTP traffic.
- A new rule option ‘byte_extract’ that allows extracted values to be used in subsequent rule options for isdataat, byte_test, byte_jump, and content distance/within/depth/offset.
- Updates to SMTP preprocessor to support MIME attachment decoding across multiple packets.
- Ability to “test” drop rules using Inline Test Mode. Snort will indicate a packet would have been dropped in the unified2 or console event log if policy mode was set to inline.
- Two new rule options to support base64 decoding of certain pieces of data and inspection of the base64 data via subsequent rule options.
- Updates to the Snort packet decoders for IPv6 for improvements to anomaly detection.
- Added a new pattern matcher that supports Intel’s Quick Assist Technology for improved performance on supported hardware platforms.
- Reference applications for reading unified2 output that handle all unified2 record formats used by Snort.