Tuesday, January 12, 2010

ET Rules and /\s?/

It was recently brought to my attention that many of the rules within the various Emerging Threats ruleset have a whitespace after value definitions such as flowbits:set and msg:"\s?". Unfortunately I did not notice this within the ET rulesets.

PulledPork was originally written to handle VRT rulesets from snort.org (none have this formatting flaw) and as such I had not accounted for it, as mentioned previously. The fix is a simple regex modification to the PulledPork code, you can get the patch here: http://pulledpork.googlecode.com/files/pp_304_whitespace.patch and apply it to pulledpork.pl.

For those that might ask the question "what if there are multiple whitespaces, ala \s*" this is NOT the case, I spoke with rotorhead from the ET team and all ET rules are normalized to atleast remove multiple whitespace chars.

This fix has already been checked into svn but I will not be re-releasing 0.3.4 to account for this.. but will likely be generating daily snapshots in the near future.


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