Suricata

Given a rule like:

content:"AAAA"; fast_pattern:only; content:"BBBB"; http_raw_uri; content:"AAAA"; distance:0; http_raw_uri;

The distance will end up checking the the first occurrence of content for "fast_pattern:only" instead of the previous content, as its not looking for the previous content on the http_raw_uri list.

If the rule is modified to have the distance after http_raw_uri, eg:

content:"AAAA"; fast_pattern:only; content:"BBBB"; http_raw_uri; content:"AAAA"; http_raw_uri; distance:0;

then the correct contents is checked as the rule parsing context is on the correct list.

However, from the rule writers perspective these 2 variations should result in the same outcome.