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FPs with rule 953120 for gzip data

See original GitHub issue

Description

I’m experiencing lots of FPs with rule 953120 for Content-encoding: gzip data. In all cases i analyzed, FPs were caused by these strings in gzip data:

<?\t
<?\r

I suggest following solutions:

Ceating sibling rule in PL2 for pattern <\?\s+.
Chaining rule which checks that Content-encoding != gzip. (Can we really trust it?)
Chaining rule which checks for gzip magic number in RESPONSE_BODY. (What about other encodings, for example Brotli?)

I’m voting for (1). I can send a PR for any.

Issue Analytics

State:
Created a year ago
Reactions:1
Comments:7 (7 by maintainers)

Top GitHub Comments

1reaction

azuritcommented, Aug 18, 2022

Yes i meant it just like you wrote it.

0reactions

azuritcommented, Oct 4, 2022

@dune73 I have more info here: Solution number 3 is back in the game as I enabled brotli instead of gzip to see what happens and FPs are gone. I was testing it for about a month and there was no single FP similar to one above. Problematic data may be somehow related/tied to how gzip works.

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