ModSecurity Docker Image

Supported tags and respective Dockerfile links

• 3, 3.0, 3.0.4, nginx (master/v3-nginx/Dockerfile) – last stable ModSecurity v3 on Nginx 1.17 official base image
• 2, 2.9, 2.9.3, apache (master/v2-apache/Dockerfile) – last stable ModSecurity v2 on Apache 2.4 official base image

Older tagging scheme (soon to be deprecated)

• 3.0.3-nginx, 3.0-nginx,3-nginx, latest (3.0/nginx/nginx/Dockerfile)
• 3.0.3-apache, 3.0-apache, 3-apache (3.0/apache/httpd/Dockerfile)
• 2.9.3-apache,2.9-apache, 2-apache (2.9/apache/httpd/Dockerfile)
• 2.9.3-nginx, 2.9-nginx, 2-nginx (2.9/nginx/nginx/Dockerfile)
• 2.9-apache-ubuntu (2.9/apache/ubuntu/Dockerfile)
• 2.9-nginx-ubuntu (2.9/nginx/ubuntu/Dockerfile)

Quick reference

• Where to get help

  The CRS-Support Docker Repo, The Core Rule Set Slack Channel (#coreruleset on owasp.slack.com), or Stack Overflow

• Where to file issues

  The Core Rule Set Docker Repo

• Maintained By

  The OWASP Core Rule Set maintainers

What is ModSecurity

ModSecurity is an open source, cross platform Web Application Firewall (WAF) engine for Apache, IIS and Nginx. It has a robust event-based programming language which provides protection from a range of attacks against web applications and allows for HTTP traffic monitoring, logging and real-time analysis.

How to use this image

This image only contains ModSecurity built from the code provided on the ModSecurity Github Repo. THE CORE RULE SET IS NOT PROVIDED IN THIS IMAGE, but it should not be hard to extend. On the other hand, IF YOU WANT MODSECURITY WITH THE CORE RULE SET please visit the OWASP Core Rule Set (CRS) DockerHub Repo.

1. Create a Dockerfile in your project and copy your code into container.

   FROM modsecurity:2-apache
   COPY ./public-html/ .
   

2. run the commands to build and run the Docker image.

   $ docker build -t my-modsec .
   $ docker run -p 8080:80 my-modsec
   

3. Visit http://localhost:8080 and your page.

TLS/HTTPS

The TLS is configured by default on port 443. Note: The default configuration uses self signed certificates, to use your own certificates (recommended) COPY or mount (-v) your server.crt and server.key into /usr/local/apache2/conf/. Please remember you'll need to forward the HTTPS port.

$ docker build -t my-modsec .
$ docker run -p 8443:443 my-modsec

Proxying

ModSecurity is often used as a reverse proxy. This allows one to use ModSecurity without modifying the webserver hosting the underlying application (and also protect web servers that modsecurity cannot currently embedd into). The proxy is set by default to true and the location is defined by BACKEND environment variable. The SSL is enabled by default.

$ docker build -t my-modsec . -f
$ docker run -p 8080:80 -e PROXY_SSL=on -e BACKEND=http://example.com my-modsec

ServerName

It is often convenient to set your servername. To do this simply use the SERVER_NAME environment variable passed to docker run. By default the servername provided is localhost.

$ docker build -t modsec .
$ docker run -p 8080:80 -e SERVER_NAME=myhost my-modsec

Apache ENV Variables

• ACCESSLOG - A string value indicating the location of the custom log file (Default: /var/log/apache2/access.log)
• BACKEND - A string indicating the partial URL for the remote server of the ProxyPass directive (Default: http://localhost:80)
• BACKEND_WS - A string indicating the IP/URL of the WebSocket service (Default: ws://localhost:8080)
• ERRORLOG - A string value indicating the location of the error log file (Default: /var/log/apache2/error.log)
• H2_PROTOCOLS - A string value indicating the protocols supported by the HTTP2 module (Default: h2 http/1.1)
• LOGLEVEL - A string value controlling the number of messages logged to the error_log (Default: warn)
• METRICS_ALLOW_FROM - A string indicating a range of IP adresses that can access the metrics (Default: 127.0.0.0/255.0.0.0 ::1/128)
• METRICS_DENY_FROM - A string indicating a range of IP adresses that cannot access the metrics (Default: All)
• METRICSLOG - A string indicating the path of the metrics log (Default: /dev/null combined)
• PERFLOG - A string indicating the path of the performance log (Default: /dev/stdout perflogjson env=write_perflog)
• PORT - An integer value indicating the port where the webserver is listening to (Default: 80)
• PROXY_PRESERVE_HOST - A string indicating the use of incoming Host HTTP request header for proxy request (Default: on)
• PROXY_SSL_CERT_KEY - A string indicating the path to the server PEM-encoded private key file (Default: /usr/local/apache2/conf/server.key)
• PROXY_SSL_CERT - A string indicating the path to the server PEM-encoded X.509 certificate data file or token identifier (Default: /usr/local/apache2/conf/server.crt)
• PROXY_SSL_CHECK_PEER_NAME - A string indicating if the host name checking for remote server certificates is to be enabled (Default: on)
• PROXY_SSL_VERIFY - A string value indicating the type of remote server Certificate verification (Default: none)
• PROXY_SSL - A string indicating SSL Proxy Engine Operation Switch (Default: off)
• PROXY_TIMEOUT - Number of seconds for proxied requests to time out (Default: 60)
• REMOTEIP_INT_PROXY - A string indicating the client intranet IP addresses trusted to present the RemoteIPHeader value (Default: 10.1.0.0/16)
• SERVER_ADMIN - A string value indicating the address where problems with the server should be e-mailed (Default: root@localhost)
• REQ_HEADER_FORWARDED_PROTO - A string indicating the transfer protocol of the initial request (Default: https)
• SSL_ENGINE - A string indicating the SSL Engine Operation Switch (Default: off)
• TIMEOUT - Number of seconds before receiving and sending timeout (Default: 60)
• WORKER_CONNECTIONS - Maximum number of MPM request worker processes (Default: 400)

Nginx ENV Variables

• ACCESSLOG - A string value indicating the location of the access log file (Default: /var/log/nginx/access.log)
• BACKEND - A string indicating the partial URL for the remote server of the proxy_pass directive (Default: http://localhost:80)
• DNS_SERVER - A string indicating the name servers used to resolve names of upstream servers into addresses. For localhost backend this value should not be defined (Default: not defined)
• ERRORLOG - A string value indicating the location of the error log file (Default: /proc/self/fd/2)
• LOGLEVEL - A string value controlling the number of messages logged to the error_log (Default: warn)
• METRICS_ALLOW_FROM - A string indicating a single range of IP adresses that can access the metrics (Default: 127.0.0.0/24)
• METRICS_DENY_FROM - A string indicating a range of IP adresses that cannot access the metrics (Default: all)
• METRICSLOG - A string value indicating the location of metrics log file (Default: /dev/null)
• PORT - An integer value indicating the port where the webserver is listening to (Default: 80)
• PROXY_SSL_CERT_KEY - A string value indicating the path to the server PEM-encoded private key file (Default: /etc/nginx/conf/server.key)
• PROXY_SSL_CERT - A string value indicating the path to the server PEM-encoded X.509 certificate data file or token value identifier (Default: /etc/nginx/conf/server.crt)
• PROXY_SSL_VERIFY - A string value indicating if the client certificates should be verified (Default: on)
• PROXY_TIMEOUT - Number of seconds for proxied requests to time out connections (Default: 60s)
• SSL_PORT - Port number where the SSL enabled webserver is listening (Default: 443)
• TIMEOUT - Number of seconds for a keep-alive client connection to stay open on the server side (Default: 60s)
• WORKER_CONNECTIONS - Maximum number of simultaneous connections that can be opened by a worker process (Default: 1024)

ModSecurity ENV Variables

• MODSEC_AUDIT_LOG - A string indicating the path to the main audit log file or the concurrent logging index file (Default: /dev/stdout)
• MODSEC_AUDIT_LOG_FORMAT - A string indicating the output format of the AuditLogs (Default: JSON)
• MODSEC_AUDIT_LOG_TYPE - A string indicating the type of audit logging mechanism to be used (Default: Serial)
• MODSEC_AUDIT_STORAGE - A string indicating the directory where concurrent audit log entries are to be stored (Default: /var/log/modsecurity/audit/)
• MODSEC_DATA_DIR - A string indicating the path where persistent data (e.g., IP address data, session data, and so on) is to be stored (Default: /tmp/modsecurity/data)
• MODSEC_DEBUG_LOG - A string indicating the path to the ModSecurity debug log file (Default: /dev/null)
• MODSEC_DEBUG_LOGLEVEL - An integer indicating the verboseness of the debug log data (Default: 0)
• MODSEC_PCRE_MATCH_LIMIT - An integer value indicating the limit for the number of internal executions in the PCRE function (Default: 100000)
• MODSEC_PCRE_MATCH_LIMIT_RECURSION - An integer value indicating the limit for the depth of recursion when calling PCRE function (Default: 100000)
• MODSEC_REQ_BODY_ACCESS - A string value allowing ModSecurity to access request bodies (Default: on)
• MODSEC_REQ_BODY_LIMIT - An integer value indicating the maximum request body size accepted for buffering (Default: 13107200)
• MODSEC_REQ_BODY_NOFILES_LIMIT - An integer indicating the maximum request body size ModSecurity will accept for buffering (Default: 131072)
• MODSEC_RESP_BODY_ACCESS - A string value allowing ModSecurity to access response bodies (Default: on)
• MODSEC_RESP_BODY_LIMIT - An integer value indicating the maximum response body size accepted for buffering (Default: 1048576)
• MODSEC_RULE_ENGINE - A string value enabling ModSecurity itself (Default: on)
• MODSEC_TAG - A string indicating the default tag action, which will be inherited by the rules in the same configuration context (Default: modsecurity)
• MODSEC_TMP_DIR - A string indicating the path where temporary files will be created (Default: /tmp/modsecurity/tmp)
• MODSEC_UPLOAD_DIR - A string indicating the path where intercepted files will be stored (Default: /tmp/modsecurity/upload)