Integer overflow in the TCP stream reassembly module (stream4) for Snort 2.0 and earlier allows remote attackers to execute arbitrary code via large sequence numbers in packets, which enable a heap-based buffer overflow.

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.

Stack-based buffer overflow in the Back Orifice (BO) preprocessor for Snort before 2.4.3 allows remote attackers to execute arbitrary code via a crafted UDP packet.

The frag3 preprocessor in Sourcefire Snort 2.4.3 does not properly reassemble certain fragmented packets with IP options, which allows remote attackers to evade detection of certain attacks, possibly related to IP option lengths.

The HTTP Inspect preprocessor (httpinspect) in Snort 2.4.0 through 2.4.4 allows remote attackers to bypass "uricontent" rules via a carriage return (\r) after the URL and before the HTTP declaration.