REQUEST-901-INITIALIZATION.conf

# ------------------------------------------------------------------------
# OWASP ModSecurity Core Rule Set ver.3.0.2
# Copyright (c) 2006-2017 Trustwave and contributors. All rights reserved.
#
# The OWASP ModSecurity Core Rule Set is distributed under
# Apache Software License (ASL) version 2
# Please see the enclosed LICENSE file for full details.
# ------------------------------------------------------------------------

#
# This file REQUEST-901-INITIALIZATION.conf initializes the Core Rules
# and performs preparatory actions. It also fixes errors and omissions
# of variable definitions in the file crs-setup.conf.
# The setup.conf can and should be edited by the user, this file
# is part of the CRS installation and should not be altered.
#


#
# -=[ Rules Version ]=-
#
# Rule version data is added to the "Producer" line of Section H of the Audit log:
#
# - Producer: ModSecurity for Apache/2.9.1 (http://www.modsecurity.org/); OWASP_CRS/3.0.0.
#
# Ref: https://github.com/SpiderLabs/ModSecurity/wiki/Reference-Manual#wiki-SecComponentSignature
#
SecComponentSignature "OWASP_CRS/3.0.2"

#
# -=[ Default setup values ]=-
#
# The CRS checks the tx.crs_setup_version variable to ensure that the setup
# file is included at the correct time. This detects situations where
# necessary settings are not defined, for instance if the file
# inclusion order is incorrect, or if the user has forgotten to
# include the crs-setup.conf file.
#
# If you are upgrading from an earlier version of the CRS and you are
# getting this error, please make a new copy of the setup template
# crs-setup.conf.example to crs-setup.conf, and re-apply your policy
# changes. There have been many changes in settings syntax from CRS2
# to CRS3, so an old setup file may cause unwanted behavior.
#
# If you are not planning to use the crs-setup.conf template, you must
# manually set the tx.crs_setup_version variable before including
# the CRS rules/* files.
#
# The variable is a numerical representation of the CRS version number.
# E.g., v3.0.0 is represented as 300.
#

SecRule &TX:crs_setup_version "@eq 0" \
    "id:901001,\
    phase:1,\
    deny,\
    status:500,\
    log,\
    auditlog,\
    msg:'ModSecurity Core Rule Set is deployed without configuration! Please copy the crs-setup.conf.example template to crs-setup.conf, and include the crs-setup.conf file in your webserver configuration before including the CRS rules. See the INSTALL file in the CRS directory for detailed instructions.',\
    severity:'CRITICAL'"


#
# -=[ Default setup values ]=-
#
# Some constructs or individual rules will fail if certain parameters
# are not set in the setup.conf file. The following rules will catch
# these cases and assign sane default values.
#

# Default Inbound Anomaly Threshold Level (rule 900110 in setup.conf)
SecRule &TX:inbound_anomaly_score_threshold "@eq 0" \
    "id:901100,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.inbound_anomaly_score_threshold=5'"

# Default Outbound Anomaly Threshold Level (rule 900110 in setup.conf)
SecRule &TX:outbound_anomaly_score_threshold "@eq 0" \
    "id:901110,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.outbound_anomaly_score_threshold=4'"

# Default Paranoia Level (rule 900000 in setup.conf)
SecRule &TX:paranoia_level "@eq 0" \
    "id:901120,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.paranoia_level=1'"

# Default Sampling Percentage (rule 900400 in setup.conf)
SecRule &TX:sampling_percentage "@eq 0" \
    "id:901130,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.sampling_percentage=100'"

# Default Anomaly Scores (rule 900100 in setup.conf)
SecRule &TX:critical_anomaly_score "@eq 0" \
    "id:901140,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.critical_anomaly_score=5'"

SecRule &TX:error_anomaly_score "@eq 0" \
    "id:901141,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.error_anomaly_score=4'"

SecRule &TX:warning_anomaly_score "@eq 0" \
    "id:901142,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.warning_anomaly_score=3'"

SecRule &TX:notice_anomaly_score "@eq 0" \
    "id:901143,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.notice_anomaly_score=2'"

# Default do_reput_block
SecRule &TX:do_reput_block "@eq 0" \
    "id:901150,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.do_reput_block=0'"

# Default block duration
SecRule &TX:reput_block_duration "@eq 0" \
    "id:901152,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.reput_block_duration=300'"

# Default HTTP policy: allowed_methods (rule 900200)
SecRule &TX:allowed_methods "@eq 0" \
    "id:901160,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.allowed_methods=GET HEAD POST OPTIONS'"

# Default HTTP policy: allowed_request_content_type (rule 900220)
SecRule &TX:allowed_request_content_type "@eq 0" \
    "id:901162,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.allowed_request_content_type=application/x-www-form-urlencoded|multipart/form-data|text/xml|application/xml|application/soap+xml|application/x-amf|application/json|application/octet-stream|text/plain'"

# Default HTTP policy: allowed_http_versions (rule 900230)
SecRule &TX:allowed_http_versions "@eq 0" \
    "id:901163,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.allowed_http_versions=HTTP/1.0 HTTP/1.1 HTTP/2 HTTP/2.0'"

# Default HTTP policy: restricted_extensions (rule 900240)
SecRule &TX:restricted_extensions "@eq 0" \
    "id:901164,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.restricted_extensions=.asa/ .asax/ .ascx/ .axd/ .backup/ .bak/ .bat/ .cdx/ .cer/ .cfg/ .cmd/ .com/ .config/ .conf/ .cs/ .csproj/ .csr/ .dat/ .db/ .dbf/ .dll/ .dos/ .htr/ .htw/ .ida/ .idc/ .idq/ .inc/ .ini/ .key/ .licx/ .lnk/ .log/ .mdb/ .old/ .pass/ .pdb/ .pol/ .printer/ .pwd/ .resources/ .resx/ .sql/ .sys/ .vb/ .vbs/ .vbproj/ .vsdisco/ .webinfo/ .xsd/ .xsx/'"

# Default HTTP policy: restricted_headers (rule 900250)
SecRule &TX:restricted_headers "@eq 0" \
    "id:901165,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.restricted_headers=/proxy/ /lock-token/ /content-range/ /translate/ /if/'"

# Default HTTP policy: static_extensions (rule 900260)
SecRule &TX:static_extensions "@eq 0" \
    "id:901166,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.static_extensions=/.jpg/ /.jpeg/ /.png/ /.gif/ /.js/ /.css/ /.ico/ /.svg/ /.webp/'"

# Default enforcing of body processor URLENCODED
SecRule &TX:enforce_bodyproc_urlencoded "@eq 0" \
    "id:901167,\
    phase:1,\
    pass,\
    nolog,\
    setvar:'tx.enforce_bodyproc_urlencoded=0'"

# If a default protected_uploads variable is not set in crs-setup rule 900270
# then a generic default will be set here.
SecRule &TX:protected_uploads "@eq 0" \
    "id:901180,\
    phase:1,\
    pass,\
    t:none,\
    nolog,\
    noauditlog,\
    setvar:'tx.protected_uploads=#/upload.php# #/upload.asp# #/upload.jsp#'"

#
# -=[ Initialize internal variables ]=-
#

# Initialize anomaly scoring variables.
# All _score variables start at 0, and are incremented by the various rules
# upon detection of a possible attack.
# sql_error_match is used for shortcutting rules for performance reasons.

SecAction \
    "id:901200,\
    phase:1,\
    pass,\
    t:none,\
    nolog,\
    setvar:'tx.anomaly_score=0',\
    setvar:'tx.sql_injection_score=0',\
    setvar:'tx.xss_score=0',\
    setvar:'tx.rfi_score=0',\
    setvar:'tx.lfi_score=0',\
    setvar:'tx.rce_score=0',\
    setvar:'tx.php_injection_score=0',\
    setvar:'tx.http_violation_score=0',\
    setvar:'tx.session_fixation_score=0',\
    setvar:'tx.inbound_anomaly_score=0',\
    setvar:'tx.outbound_anomaly_score=0',\
    setvar:'tx.sql_error_match=0'"


#
# -=[ Initialize collections ]=-
#
# Create both Global and IP collections for rules to use.
# There are some CRS rules that assume that these two collections
# have already been initiated.
#

SecRule REQUEST_HEADERS:User-Agent "@rx ^.*$" \
    "id:901318,\
    phase:1,\
    pass,\
    t:none,t:sha1,t:hexEncode,\
    nolog,\
    setvar:'tx.ua_hash=%{matched_var}'"

SecAction \
    "id:901321,\
    phase:1,\
    pass,\
    t:none,\
    nolog,\
    initcol:global=global,\
    initcol:ip=%{remote_addr}_%{tx.ua_hash},\
    setvar:'tx.real_ip=%{remote_addr}'"

#
# -=[ Initialize Correct Body Processing ]=-
#
# Force request body variable and optionally request body processor
#

# Force body variable
SecRule REQBODY_PROCESSOR "!@rx (?:URLENCODED|MULTIPART|XML|JSON)" \
    "id:901340,\
    phase:1,\
    pass,\
    nolog,\
    noauditlog,\
    msg:'Enabling body inspection',\
    tag:'paranoia-level/1',\
    ctl:forceRequestBodyVariable=On,\
    rev:'1',\
    ver:'OWASP_CRS/3.1.0'"

# Force body processor URLENCODED
SecRule TX:enforce_bodyproc_urlencoded "@eq 1" \
    "id:901350,\
    phase:1,\
    pass,\
    t:none,t:urlDecodeUni,\
    nolog,\
    noauditlog,\
    msg:'Enabling forced body inspection for ASCII content',\
    rev:'1',\
    ver:'OWASP_CRS/3.1.0',\
    chain"
    SecRule REQBODY_PROCESSOR "!@rx (?:URLENCODED|MULTIPART|XML|JSON)" \
        "ctl:requestBodyProcessor=URLENCODED"


#
# -=[ Easing In / Sampling Percentage ]=-
#
# This is used to send only a limited percentage of requests into the Core
# Rule Set. The selection is based on TX.sampling_percentage and a pseudo
# random number calculated below.
#
# Use this to ease into a new Core Rules installation with an existing
# productive service.
#
# See
# https://www.netnea.com/cms/2016/04/26/easing-in-conditional-modsecurity-rule-execution-based-on-pseudo-random-numbers/
#

#
# Generate the pseudo random number
#
# ATTENTION: This is no cryptographically secure random number. It's just
# a cheap way to get some random number suitable for sampling.
#
# We take the entropy contained in the UNIQUE_ID. We hash that variable and
# take the first integer numbers out of it. Theoretically, it is possible
# there are no integers in a sha1 hash. We make sure we get two
# integer numbers by taking the last two digits from the DURATION counter
# (in microseconds).
# Finally, leading zeros are removed from the two-digit random number.
#

SecRule TX:sampling_percentage "@eq 100" \
    "id:901400,\
    phase:1,\
    pass,\
    nolog,\
    skipAfter:END-SAMPLING"

SecRule UNIQUE_ID "@rx ^." \
    "id:901410,\
    phase:1,\
    pass,\
    t:sha1,t:hexEncode,\
    nolog,\
    setvar:'TX.sampling_rnd100=%{MATCHED_VAR}'"

SecRule DURATION "@rx (..)$" \
    "id:901420,\
    phase:1,\
    pass,\
    capture,\
    nolog,\
    setvar:'TX.sampling_rnd100=%{TX.sampling_rnd100}%{TX.1}'"

SecRule TX:sampling_rnd100 "@rx ^[a-f]*([0-9])[a-f]*([0-9])" \
    "id:901430,\
    phase:1,\
    pass,\
    capture,\
    nolog,\
    setvar:'TX.sampling_rnd100=%{TX.1}%{TX.2}'"

SecRule TX:sampling_rnd100 "@rx ^0([0-9])" \
    "id:901440,\
    phase:1,\
    pass,\
    capture,\
    nolog,\
    setvar:'TX.sampling_rnd100=%{TX.1}'"


#
# Sampling decision
#
# If a request is allowed to pass without being checked by the CRS, there is no
# entry in the audit log (for performance reasons), but an error log entry is
# being written.  If you want to disable the error log entry, then issue the
# following directive somewhere after the inclusion of the CRS
# (E.g., RESPONSE-999-EXCEPTIONS.conf).
#
# SecRuleUpdateActionById 901450 "nolog"
#


SecRule TX:sampling_rnd100 "!@lt %{tx.sampling_percentage}" \
    "id:901450,\
    phase:1,\
    pass,\
    log,\
    noauditlog,\
    msg:'Sampling: Disable the rule engine based on sampling_percentage \
%{TX.sampling_percentage} and random number %{TX.sampling_rnd100}.',\
    ctl:ruleEngine=Off"

SecMarker "END-SAMPLING"