Re: question about PCRE limits exceeded
Andrew Howe <[email protected]> Wed, 17 Feb 2021 14:34:53 +0000
| Newsgroups | gmane.comp.apache.mod-security.user |
|---|---|
| Message-ID | <CADi1syD574n5-RM12mUrXseTM3ym3xTF6gjj7_+AqG+oRTCOvA@mail.gmail.com> |
Hi Ed,
> This is not a rule violation, so where would I find a specification for the error it gets.
I believe that if a PCRE match limit is hit then the flag
MSC_PCRE_LIMITS_EXCEEDED is set.
A rule would be required to look for the presence of that flag and
take appropriate action if it is set.
The ModSecurity default configuration (modsecurity.conf-recommended,
https://github.com/SpiderLabs/ModSecurity/blob/v3/master/modsecurity.conf-recommended)
contains the following rule:
# Some internal errors will set flags in TX and we will need to
look for these.
# All of these are prefixed with "MSC_". The following flags
currently exist:
#
# MSC_PCRE_LIMITS_EXCEEDED: PCRE match limits were exceeded.
#
SecRule TX:/^MSC_/ "!@streq 0" \
"id:'200005',phase:2,t:none,deny,msg:'ModSecurity internal
error flagged: %{MATCHED_VAR_NAME}'"
On a ModSecurity deployment using that default rule, a request that
hits a PCRE match limit would be denied. I suppose a "status:" action
could be added to specify which response status code to use, as you
mentioned.
I hope this helps answer your question.
Thanks,
Andrew
--
Andrew Howe
Loadbalancer.org Ltd.
www.loadbalancer.org
+1 888 867 9504 / +44 (0)330 380 1064
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