Example

docker build -t owasp/modsecurity-crs .
docker run -p 80:80 -ti -e PARANOIA=4 --rm owasp/modsecurity-crs

or

docker build -t owasp/modsecurity-crs .
docker run -p 80:80 -ti -e PARANOIA=4 -e PROXY=1 --rm owasp/modsecurity-crs

Environment Variables

The following environment variables are available to configure the CRS container:

Name	Description
PARANOIA	An integer indicating the paranoia level (Default: 1)
PROXY	An integer indicating if reverse proxy mode is enabled (Default: 0)
UPSTREAM	The IP Address (and optional port) of the upstream server when proxy mode is enabled. (Default: the container's default router, port 81) (Examples: 192.0.2.2 or 192.0.2.2:80)
EXECUTING_PARANOIA	An integer indicating the executing_paranoia_level (Default: paranoia level)
ENFORCE_BODYPROC_URLENCODED	A boolean indicating the enforce_bodyproc_urlencoded (Default: 0)
ANOMALYIN	An integer indicating the inbound_anomaly_score_threshold (Default: 5)
ANOMALYOUT	An integer indicating the outbound_anomaly_score_threshold (Default: 4)
ALLOWED_METHODS	A string indicating the allowed_methods (Default: GET HEAD POST OPTIONS)
ALLOWED_REQUEST_CONTENT_TYPE	A string indicating the allowed_request_content_type (Default: application/x-www-form-urlencoded|multipart/form-data|text/xml|application/xml|application/soap+xml|application/x-amf|application/json|application/octet-stream|application/csp-report|application/xss-auditor-report|text/plain)
ALLOWED_REQUEST_CONTENT_TYPE_CHARSET	A string indicating the allowed_request_content_type_charset (Default: utf-8|iso-8859-1|iso-8859-15|windows-1252)
ALLOWED_HTTP_VERSIONS	A string indicating the allowed_http_versions (Default: HTTP/1.0 HTTP/1.1 HTTP/2 HTTP/2.0)
RESTRICTED_EXTENSIONS	A string indicating the restricted_extensions (Default: .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/)
RESTRICTED_HEADERS	A string indicating the restricted_headers (Default: /proxy/ /lock-token/ /content-range/ /if/)
STATIC_EXTENSIONS	A string indicating the static_extensions (Default: /.jpg/ /.jpeg/ /.png/ /.gif/ /.js/ /.css/ /.ico/ /.svg/ /.webp/)
MAX_NUM_ARGS	An integer indicating the max_num_args (Default: unlimited)
ARG_NAME_LENGTH	An integer indicating the arg_name_length (Default: unlimited)
ARG_LENGTH	An integer indicating the arg_length (Default: unlimited)
TOTAL_ARG_LENGTH	An integer indicating the total_arg_length (Default: unlimited)
MAX_FILE_SIZE	An integer indicating the max_file_size (Default: unlimited)
COMBINED_FILE_SIZES	An integer indicating the combined_file_sizes (Default: unlimited)

Notes regarding reverse proxy

In order to more easily test drive the CRS ruleset, we include support for an technique called Reverse Proxy. Using this technique, you keep your pre-existing web server online at a non-standard host and port, and then configure the CRS container to accept public traffic. The CRS container then proxies the traffic to your pre-existing webserver. This way, you can test out CRS with any web server. Some notes:

• Proxy is not enabled by default. You'll need to pass the -e PROXY=1 environment variable to enable it.
• You'll want to configure your typical webserver to listen on your docker interface only (i.e. 172.17.0.1:81) so that public traffic doesn't reach it.
• Do not use 127.0.0.1 as an UPSTREAM address. The loopback interface inside the docker container is not the same interface as the one on docker host.
• Note that traffic coming through this proxy will look like it's coming from the wrong address. You may want to configure your pre-existing webserver to use the X-Forwarded-For HTTP header to populate the remote address field for traffic from the proxy.

ModSecurity CRS Tuning

There are two possible ways to pass ModSecurity CRS tuning rules to the container:

• To map the ModSecurity tuning file(s) via volumes into the container during the run command
• To copy the ModSecurity tuning file(s) into the created container and then start the container

Map ModSecurity tuning file via volume

docker run -dti --rm \
   -p 80:80 \
   -v /path/to/REQUEST-900-EXCLUSION-RULES-BEFORE-CRS.conf:/etc/modsecurity.d/owasp-crs/rules/REQUEST-900-EXCLUSION-RULES-BEFORE-CRS.conf \
   -v /path/to/RESPONSE-999-EXCLUSION-RULES-AFTER-CRS.conf:/etc/modsecurity.d/owasp-crs/rules/RESPONSE-999-EXCLUSION-RULES-AFTER-CRS.conf \
   owasp/modsecurity-crs

Copy ModSecurity tuning file into created container

This example can be helpful when no volume mounts are possible (some CI pipelines).

docker create -ti --name modseccrs \
   -p 80:80 \
   owasp/modsecurity-crs
  
docker cp /path/to/RESPONSE-999-EXCLUSION-RULES-AFTER-CRS.conf \
   modseccrs:/etc/modsecurity.d/owasp-crs/rules/RESPONSE-999-EXCLUSION-RULES-AFTER-CRS.conf
  
docker start modseccrs

Full docker run example with all possible environment variables

docker run -dti 80:80 --rm \
   -e PARANOIA=1 \
   -e EXECUTING_PARANOIA=2 \
   -e ENFORCE_BODYPROC_URLENCODED=1 \
   -e ANOMALYIN=10 \
   -e ANOMALYOUT=5 \
   -e ALLOWED_METHODS="GET POST PUT" \
   -e ALLOWED_REQUEST_CONTENT_TYPE="text/xml|application/xml|text/plain" \
   -e ALLOWED_REQUEST_CONTENT_TYPE_CHARSET="utf-8|iso-8859-1" \
   -e ALLOWED_HTTP_VERSIONS="HTTP/1.1 HTTP/2 HTTP/2.0" \
   -e RESTRICTED_EXTENSIONS=".cmd/ .com/ .config/ .dll/" \
   -e RESTRICTED_HEADERS="/proxy/ /if/" \
   -e STATIC_EXTENSIONS="/.jpg/ /.jpeg/ /.png/ /.gif/" \
   -e MAX_NUM_ARGS=128 \
   -e ARG_NAME_LENGTH=50 \
   -e ARG_LENGTH=200 \
   -e TOTAL_ARG_LENGTH=6400 \
   -e MAX_FILE_SIZE=100000 \
   -e COMBINED_FILE_SIZES=1000000 \
   -e PROXY=1 \
   -e 192.0.2.2:80 \
   owasp/modsecurity-crs