CasperSecurity
# Fail2Ban filter to block web requests on a long or suspicious nature
#
[INCLUDES]
# overwrite with apache-common.local if _apache_error_client is incorrect.
before = apache-common.conf
[Definition]
failregex = ^%(_apache_error_client)s (?:(?:AH0013[456]: )?Invalid (method|URI) in request\b|(?:AH00565: )?request failed: URI too long \(longer than \d+\)|request failed: erroneous characters after protocol string:|(?:AH00566: )?request failed: invalid characters in URI\b)
ignoreregex =
# DEV Notes:
#
# [sebres] Because this apache-log could contain very long URLs (and/or referrer),
# the parsing of it anchored way may be very vulnerable (at least as regards
# the system resources, see gh-1790). Thus rewritten without end-anchor ($).
#
# fgrep -r 'URI too long' httpd-2.*
# httpd-2.2.25/server/protocol.c: "request failed: URI too long (longer than %d)", r->server->limit_req_line);
# httpd-2.4.4/server/protocol.c: "request failed: URI too long (longer than %d)",
#
# fgrep -r 'in request' ../httpd-2.* | fgrep Invalid
# httpd-2.2.25/server/core.c: "Invalid URI in request %s", r->the_request);
# httpd-2.2.25/server/core.c: "Invalid method in request %s", r->the_request);
# httpd-2.2.25/docs/manual/rewrite/flags.html.fr:avertissements 'Invalid URI in request'.
# httpd-2.4.4/server/core.c: "Invalid URI in request %s", r->the_request);
# httpd-2.4.4/server/core.c: "Invalid method in request %s - possible attempt to establish SSL connection on non-SSL port", r->the_request);
# httpd-2.4.4/server/core.c: "Invalid method in request %s", r->the_request);
#
# fgrep -r 'invalid characters in URI' httpd-2.*
# httpd-2.4.4/server/protocol.c: "request failed: invalid characters in URI");
#
# http://svn.apache.org/viewvc/httpd/httpd/trunk/server/core.c?r1=739382&r2=739620&pathrev=739620
# ...possible attempt to establish SSL connection on non-SSL port
#
# https://wiki.apache.org/httpd/ListOfErrors
# Author: Tim Connors