ModSecurity/rules/modsecurity_crs_21_protocol_anomalies.conf
2008-04-24 16:48:08 +00:00

68 lines
3.5 KiB
Plaintext

# ---------------------------------------------------------------
# Core ModSecurity Rule Set ver.1.6.1
# Copyright (C) 2006-2007 Breach Security Inc. All rights reserved.
#
# The ModSecuirty Core Rule Set is distributed under GPL version 2
# Please see the enclosed LICENCE file for full details.
# ---------------------------------------------------------------
#
# TODO in some cases a valid client (usually automated) generates requests that
# violates the HTTP protocol. Create exceptions for those clients, but try
# to limit the exception to a source IP or other additional properties of
# the request such as URL and not allow the violation generally.
#
# Do not accept requests without common headers.
# Implies either an attacker or a legitimate automation client.
#
# Exception for Apache SSL pinger
SecRule REQUEST_LINE "^GET /$" "chain,phase:2,t:none,pass,nolog,ctl:ruleRemoveById=960019,ctl:ruleRemoveById=960008,ctl:ruleRemoveById=960015,ctl:ruleRemoveById=960009,id:'999210',severity:'5'"
SecRule REMOTE_ADDR "^127\.0\.0\.1$" t:none
# Exception for Apache internal dummy connection
SecRule REQUEST_LINE "^GET / HTTP/1.0$" "chain,phase:2,t:none,pass,nolog,ctl:ruleRemoveById=960019,ctl:ruleRemoveById=960008,ctl:ruleRemoveById=960015,ctl:ruleRemoveById=960009,id:'999211',severity:'5'"
SecRule REMOTE_ADDR "^127\.0\.0\.1$" "chain,t:none"
SecRule REQUEST_HEADERS:User-Agent "^Apache.*\(internal dummy connection\)$" "t:none"
# Detect HTTP/0.9 Requests
SecRule REQUEST_PROTOCOL ^http/0.9$ "t:none,t:lowercase,phase:2,log,auditlog,msg:'HTTP/0.9 Request Detected',id:'960019',severity:'4'"
SecRule &REQUEST_HEADERS:Host "@eq 0" \
"skip:1,phase:2,t:none,log,auditlog,msg:'Request Missing a Host Header',id:'960008',tag:'PROTOCOL_VIOLATION/MISSING_HEADER',severity:'4'"
SecRule REQUEST_HEADERS:Host "^$" \
"phase:2,t:none,log,auditlog,msg:'Request Missing a Host Header',id:'960008',tag:'PROTOCOL_VIOLATION/MISSING_HEADER',severity:'4'"
SecRule &REQUEST_HEADERS:Accept "@eq 0" \
"chain,phase:2,skip:1,t:none,log,auditlog,msg:'Request Missing an Accept Header', severity:'2',id:'960015',tag:'PROTOCOL_VIOLATION/MISSING_HEADER'"
SecRule REQUEST_METHOD "!^OPTIONS$" "t:none"
SecRule REQUEST_HEADERS:Accept "^$" \
"chain,phase:2,t:none,log,auditlog,msg:'Request Missing an Accept Header', severity:'2',id:'960015',tag:'PROTOCOL_VIOLATION/MISSING_HEADER'"
SecRule REQUEST_METHOD "!^OPTIONS$" "t:none"
SecRule &REQUEST_HEADERS:User-Agent "@eq 0" \
"skip:1,phase:2,t:none,log,auditlog,msg:'Request Missing a User Agent Header',id:'960009',tag:'PROTOCOL_VIOLATION/MISSING_HEADER',severity:'4'"
SecRule REQUEST_HEADERS:User-Agent "^$" \
"t:none,log,auditlog,msg:'Request Missing a User Agent Header',id:'960009',tag:'PROTOCOL_VIOLATION/MISSING_HEADER',severity:'4'"
SecRule &REQUEST_HEADERS:Content-Type "@eq 0" \
"chain,phase:2,t:none,log,auditlog,msg:'Request Containing Content, but Missing Content-Type header',id:'960904',severity:'4'"
SecRule REQUEST_HEADERS:Content-Length "!^0$" "t:none"
# Check that the host header is not an IP address
#
SecRule REQUEST_HEADERS:Host "^[\d\.]+$" "phase:2,t:none,deny,log,auditlog,status:400,msg:'Host header is a numeric IP address', severity:'2',id:'960017',tag:'PROTOCOL_VIOLATION/IP_HOST'"
# Log a security event when the request is rejected by apache
#
SecRule RESPONSE_STATUS ^400$ "t:none,phase:5,chain,log,auditlog,pass,msg:'Invalid request',id:'960913',severity:'2'"
SecRule WEBSERVER_ERROR_LOG !ModSecurity "t:none"