owasp-modsecurity / owasp-modsecurity/ModSecurity
Target transformed even when ignored via ctl: action
Open
Nobody has claimed this yet.
2.x
bug
- Dominant language
- C++
- Stars
- 9.8k
- Forks
- 1.8k
- Avg merge
- 2h 46m
- Merged PRs (30d)
- 1
Description
v2 master
When ignoring some targets, like a huge ARG, it's not matched but still transformed.
In some cases (several big ARGS), it can have dramatic impacts on performance.
Debug log showing the problem (ARGS:ParamToIgnore=a%2520b):
[9] fetch_target_exception: Found exception target list [ARGS:ParamToIgnore] for rule id 2000415
[9] fetch_target_exception: Target ARGS:ParamToIgnore will not be processed.
[4] Executing operator "rx" with param "a" against ARGS:ParamToIgnore skipped.
[9] T (0) urlDecode: "a b"
[9] T (0) htmlEntityDecode: "a b"
[9] T (0) jsDecode: "a b"
[9] T (0) compressWhitespace: "a b"
[9] T (0) lowercase: "a b"
[4] Rule returned 0.
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the behavior using the shown ARGS:ParamToIgnore example and inspect the target-ignore path around fetch_target_exception and the transformation trace. Done means an ignored target is not transformed and the performance impact from large ignored arguments is avoided.
Written by the indexing model from the issue text.
Assessment
- Domain
- performance, security
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100