# modsecurity-crs-docker

**Repository Path**: flashpig8014/modsecurity-crs-docker

## Basic Information

- **Project Name**: modsecurity-crs-docker
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-07-05
- **Last Updated**: 2024-07-05

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# OWASP CRS Docker Image

[![dockeri.co](http://dockeri.co/image/owasp/modsecurity-crs)](https://hub.docker.com/r/owasp/modsecurity-crs/)

[![Build Status](https://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Fcoreruleset%2Fmodsecurity-crs-docker%2Fbadge%3Fref%3Dmaster&style=flat)](https://actions-badge.atrox.dev/coreruleset/modsecurity-crs-docker/goto?ref=master
) [![GitHub issues](https://img.shields.io/github/issues-raw/coreruleset/modsecurity-crs-docker.svg)](https://github.com/coreruleset/modsecurity-crs-docker/issues
) [![GitHub PRs](https://img.shields.io/github/issues-pr-raw/coreruleset/modsecurity-crs-docker.svg)](https://github.com/coreruleset/modsecurity-crs-docker/pulls
) [![License](https://img.shields.io/github/license/coreruleset/modsecurity-crs-docker.svg)](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/LICENSE)

## What is the OWASP CRS

OWASP CRS is a set of generic attack detection rules for use with ModSecurity or compatible web application firewalls.
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx.

## Supported Tags

### Stable Tags

Stable Tags are composed of:
   * CRS version, in the fromat `<major>[.<minor>[.<patch]]`
   * web server variant
   * OS variant (optional)
   * date, in the format `YYYYMMDDHHMM`

The stable tag format is `<CRS version>-<web server>[-<os>]-<date>`.
Examples:
   * `4-nginx-202401121309`
   * `4.0-apache-alpine-202401121309`
   * `4.0.0-openresty-alpine-fat-202401121309`

### Rolling Tags

Rolling tags are updated whenever a new stable tag release occurs. Rolling tags can be practical but should not be used in production.

Rolling Tags are composed of:
   * web server variant
   * OS variant (optional)

The stable tag format is `<web server>[-<os>]`.
Examples:
   * `nginx`
   * `apache-alpine`
   * `openresty-alpine-fat`

## OS Variants

* nginx – *latest stable ModSecurity v3 on Nginx 1.27.0 official stable base image, and latest stable OWASP CRS 4.4.0*
   * [nginx](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/nginx/Dockerfile)
   * [nginx-alpine](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/nginx/Dockerfile-alpine)
* Openresty - *last stable ModSecurity v3 on OpenResty 1.25.3.1 official stable base image, and latest stable OWASP CRS 4.4.0*
   * [openresty-alpine-fat](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/openresty/Dockerfile-alpine)
* Apache httpd – *last stable ModSecurity v2 on Apache 2.4.61 official stable base image, and latest stable OWASP CRS 4.4.0*
   * [apache](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/apache/Dockerfile)
   * [apache-alpine](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/apache/Dockerfile-alpine)

### Notes regarding Openresty version of this image

We currently only provide a version of the Openresty image based on **Alpine Linux**. The Dockerfile for Openresty resides in the [docker-openresty repository](https://github.com/openresty/docker-openresty/blob/master/alpine/Dockerfile.fat).

## Supported architectures

Our builds are based on the official Apache httpd, nginx and Openresty images, which means we can only support the architectures they support.

We currently provide images for the following architectures:

* linux/amd64
* linux/arm/v7
* linux/arm64/v8
* linux/i386

### Building

We require a version of `buildx` >= v0.9.1. [Visit the official documentation](https://docs.docker.com/build/architecture/#install-buildx) for instructions on installing and upgrading `buildx`. You can check which version you have using:

```bash
docker buildx version
github.com/docker/buildx v0.9.1 ed00243a0ce2a0aee75311b06e32d33b44729689
```

If you want to see the targets of the build, use:

```bash
docker buildx bake -f ./docker-bake.hcl --print
```

To build for any platforms of your choosing, just use this example:

```bash
docker buildx create --use --platform linux/amd64,linux/i386,linux/arm64,linux/arm/v7
docker buildx bake -f docker-bake.hcl
```

To build a specific target for a single platform only (replace target and platform strings in the example with the your choices):

```bash
docker buildx bake -f docker-bake.hcl --set "*.platform=linux/amd64" nginx-alpine
```

### Notes regarding Openresty version of the image

Openresty image builds currently support only these architectures:

* linux/amd64
* linux/arm64

## Container Health Checks

🆕 We add healthchecks to the images, so that containers return HTTP status code 200 from the `/healthz` endpoint. When a container has a healthcheck specified, it has a _health status_ in addition to its normal status. This status is initially `starting`. Whenever a health check passes, it becomes `healthy` (whatever state it was previously in). After a certain number of consecutive failures, it becomes `unhealthy`. See <https://docs.docker.com/engine/reference/builder/#healthcheck> for more information.

## CRS Versions

> Hey, I used some specific git version with the containers? What happened?

You can achieve the same results just by getting any version you want, and using docker volumes. See this example:

```bash
git clone https://github.com/coreruleset/coreruleset.git myrules
cd myrules
git checkout ac2a0d1
docker run -p 8080:8080 -ti -e PARANOIA=4 -v rules:/opt/owasp-crs/rules:ro --rm owasp/modsecurity-crs
```

## Quick reference

* **Where to get help**: the [OWASP CRS container repo](https://github.com/coreruleset/modsecurity-crs-docker), the [OWASP CRS Slack channel](https://owasp.org/slack/invite) (#coreruleset on owasp.slack.com), or [Stack Overflow](https://stackoverflow.com/questions/tagged/mod-security)

* **Where to file issues**: the [OWASP CRS container repo](https://github.com/coreruleset/modsecurity-crs-docker)

* **Maintained By**: The CRS project 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.

### Nginx based images breaking change

| ⚠️ WARNING          |
|:---------------------------|
| Nginx based images are now based on upstream nginx. This changed the way the config file for nginx is generated.  |

If using the [Nginx environment variables](https://github.com/coreruleset/modsecurity-crs-docker#nginx-env-variables) is not enough for your use case, you can mount your own `nginx.conf` file as the new template for generating the base config.

An example can be seen in the [docker-compose](https://github.com/coreruleset/modsecurity-crs-docker/blob/master/docker-compose.yaml) file.

> 💬 What happens if I want to make changes in a different file, like `/etc/nginx/conf.d/default.conf`?
> You mount your local file, e.g. `nginx/default.conf` as the new template: `/etc/nginx/templates/conf.d/default.conf.template`. You can do this similarly with other files. Files in the templates directory will be copied and subdirectories will be preserved.

Both nginx and httpd containers now run with an **unprivileged user**. This means that we cannot bind to ports below 1024, so you might need to correct your `PORT` and `SSL_PORT` settings. Now the defaults for both nginx and httpd are `8080` and `8443`.

### Common ENV Variables

These variables are common to image variants and will set defaults based on the image name.
| Name | Description | httpd default | nginx / Openresty default (if different) |
| -- | -- | -- | -- |
| ACCESSLOG | Location of the custom log file | `/var/log/apache2/access.log` | `/var/log/nginx/access.log` |
| BACKEND | Partial URL for the remote server of the `ProxyPass` (httpd) and `proxy_pass` (nginx) directives | `http://localhost:80` | - |
| ERRORLOG | Location of the error log file | `/proc/self/fd/2` | - |
| LOGLEVEL | Minimum level for log messages to be logged to the error log | `warn` | - |
| METRICS_ALLOW_FROM | A single range of IP adresses that can access the metrics | `127.0.0.0/255.0.0.0 ::1/128` | `127.0.0.0/24` |
| METRICS_DENY_FROM | A range of IP adresses that cannot access the metrics | `All` | `all` |
| METRICSLOG | Location of metrics log file | `/dev/null` | - |
| PROXY_SSL_CERT | A string indicating the path to the PEM-encoded X.509 certificate data file or token identifier of the proxied server | `/usr/local/apache2/conf/proxy.crt` | `/etc/nginx/conf/proxy.crt` / `/usr/local/openresty/nginx/conf/proxy.crt` |
| PROXY_SSL_CERT_KEY | A string indicating the path to the PEM-encoded private key file of the proxied server | `/usr/local/apache2/conf/proxy.key` | `/etc/nginx/conf/proxy.key` / `/usr/local/openresty/nginx/conf/proxy.key` |
| PROXY_SSL_CIPHERS| A string indicating the cipher suite to connect to the backend via TLS | `"ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384"` | - |
| PROXY_SSL_PROTOCOLS | TLS protocols to enable for the connection to the backend | `"all -SSLv3 -TLSv1 -TLSv1.1"` | `TTLSv1.2 TLSv1.3` |
| PROXY_SSL  | SSL Proxy Engine Operation Switch | `off` | - |
| PROXY_SSL_VERIFY | A string value indicating the type of proxy server Certificate verification | `none` | `off` |
| PROXY_TIMEOUT  | Number of seconds for proxied requests to time out | `60` | `60s` |
| SERVER_NAME | The server name | `localhost` | - |
| SSL_CERT | A string indicating the path to the PEM-encoded X.509 certificate data file or token identifier of the proxied server | `/usr/local/apache2/conf/server.crt` | `/etc/nginx/conf/server.crt` / `/usr/local/openresty/nginx/conf/server.crt` |
| SSL_CERT_KEY | A string indicating the path to the PEM-encoded private key file of the proxied server | `/usr/local/apache2/conf/server.key` | `/etc/nginx/conf/server.key` / `/usr/local/openresty/nginx/conf/server.key` |
| SSL_CIPHERS| A string indicating the cipher suite for incoming TLS connections | `"ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384"` | - |
| SSL_OCSP_STAPLING | Enable / disable OCSP stapling | `On` | `on` |
| SSL_PROTOCOLS | TLS protocols to enable for the connection to the backend | `"all -SSLv3 -TLSv1 -TLSv1.1"` | `TTLSv1.2 TLSv1.3` |

### Apache ENV Variables

| Name     | Description|
| -------- | ------------------------------------------------------------------- |
| APACHE_ALWAYS_TLS_REDIRECT | A string value indicating if http should redirect to https (Allowed values: `on`, `off`. Default: `off`) |
| APACHE_ERRORLOG_FORMAT | A string value indicating the `ErrorLogFormat` that Apache should use. (Default: `'"[%{u}t] [%-m:%l] [pid %P:tid %T] %7F: %E: [client\ %a] %M% ,\ referer\ %{Referer}i"'` |
| APACHE_LOGFORMAT | A string value indicating the LogFormat that apache should use. (Default: `'"%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""'` (combined). Tip: use single quotes outside your double quoted format string.) ⚠️ Do not add a `|` as part of the log format. It is used internally.  |
| APACHE_METRICS_LOGFORMAT | A string value indicating the LogFormat that the additional log apache metrics should use. (Default:'"%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""' (combined). Tip: use single quotes outside your double quoted format string.) ⚠️ Do not add a `|` as part of the log format. It is used internally.  |
| BACKEND_WS | A string indicating the IP/URL of the WebSocket service (Default: `ws://localhost:8081`) |
| H2_PROTOCOLS  | A string value indicating the protocols supported by the HTTP2 module (Default: `h2 http/1.1`) |
| MUTEX | Configure mutex and lock file directory for all specified mutexes (see [Mutex](https://httpd.apache.org/docs/2.4/mod/core.html#mutex)) (Default: `default`) |
| PORT | An int value indicating the port where the webserver is listening to | `8080` | - |
| PROXY_ERROR_OVERRIDE  | A string indicating that errors from the backend services should be overridden by this proxy server (see [ProxyErrorOverride](https://httpd.apache.org/docs/2.4/mod/mod_proxy.html#proxyerroroverride) directive). (Allowed values: `on`, `off`. Default: `on`) |
| PROXY_PRESERVE_HOST  | A string indicating the use of incoming Host HTTP request header for proxy request (Default: `on`) |
| PROXY_SSL_CA_CERT  | A string indicating the path to the PEM-encoded list of accepted CA certificates for the proxied server (Default: `/etc/ssl/certs/ca-certificates.ca`) |
| PROXY_SSL_CHECK_PEER_NAME  | A string indicating if the host name checking for remote server certificates is to be enabled (Default: `on`) |
| REMOTEIP_INT_PROXY  | A string indicating the client intranet IP addresses trusted to present the RemoteIPHeader value (Default: `10.1.0.0/16`) |
| REQ_HEADER_FORWARDED_PROTO  | A string indicating the transfer protocol of the initial request (Default: `https`) |
| SERVER_ADMIN  | A string value indicating the address where problems with the server should be e-mailed (Default: `root@localhost`) |
| SERVER_SIGNATURE | A string value configuring the footer on server-generated documents (Allowed values: `On`, `Off`, `EMail`. Default: `Off`) |
| SERVER_TOKENS | Option defining the server information presented to clients in the `Server` HTTP response header. Also see `MODSEC_SERVER_SIGNATURE`. (Allowed values: `Full`, `Prod[uctOnly]`, `Major`, `Minor`, `Min[imal]`, `OS`. Default: `Full`). |
| SSL_ENGINE  | A string indicating the SSL Engine Operation Switch (Default: `on`) |
| SSL_HONOR_CIPHER_ORDER | A string indicating if the server should [honor the cipher list provided by the client](https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslhonorcipherorder) (Allowed values: `on`, `off`. Default: `off`) |
| SSL_PORT | Port number where the SSL enabled webserver is listening | `8443` | - |
| SSL_SESSION_TICKETS | A string to enable or disable the use of [TLS session tickets](https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslsessiontickets) (RFC 5077). (Default: `off`) |
| TIMEOUT  | Number of seconds before receiving and sending timeout (Default: `60`) |
| WORKER_CONNECTIONS  | Maximum number of MPM request worker processes (Default: `400`) |

> [!NOTE]
> Apache access and metric logs can be disabled by exporting the `nologging=1` environment variable, or using `ACCESSLOG=/dev/null` and `METRICSLOG=/dev/null`.

### Nginx ENV Variables

| Name     | Description|
| -------- | ------------------------------------------------------------------- |
| 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_) |
| KEEPALIVE_TIMEOUT  | Number of seconds for a keep-alive client connection to stay open on the server side (Default: `60s`) |
| NGINX_ALWAYS_TLS_REDIRECT | A string value indicating if http should redirect to https (Allowed values: `on`, `off`. Default: `off`) |
| PORT | An int value indicating the port where the webserver is listening to | `8080` | We run as unprivileged user. |
| PROXY_SSL_VERIFY_DEPTH  | An integer value indicating the verification depth for the client certificate chain (Default: `1`) |
| REAL_IP_HEADER | Name of the header containing the real IP value(s) (Default: `X-REAL-IP`). See [real_ip_header](http://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_header) |
| REAL_IP_PROXY_HEADER | Name of the header containing `$remote_addr` to be passed to proxy (Default: `X-REAL-IP`). See [proxy_set_header](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_set_header) |
| REAL_IP_RECURSIVE | A string value indicating whether to use recursive reaplacement on addresses in `REAL_IP_HEADER` (Allowed values: `on`, `off`. Default: `on`). See [real_ip_recursive](http://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_recursive) |
| SERVER_TOKENS | A boolean value for enabling / disabling emission of server identifying information in the `Server` HTTP response header and on error pages. (Allowed values: `on`, `off`, `build`. Default: `off`). |
| SET_REAL_IP_FROM | A string of comma separated IP, CIDR, or UNIX domain socket addresses that are trusted to replace addresses in `REAL_IP_HEADER` (Default: `127.0.0.1`). See [set_real_ip_from](http://nginx.org/en/docs/http/ngx_http_realip_module.html#set_real_ip_from) |
| SSL_DH_BITS | A numeric value indicating the size (in bits) to use for the generated DH-params file (Default 2048) |
| SSL_PORT | Port number where the SSL enabled webserver is listening | `8443` | We run as unprivileged user. |
| SSL_PREFER_CIPHERS | A string value indicating if the server ciphers should be preferred over client ciphers when using the SSLv3 and TLS protocols (Allowed values: `on`, `off`. Default: `off`)|
| SSL_VERIFY  | A string value indicating if the client certificates should be verified (Allowed values: `on`, `off`. Default: `off`) |
| SSL_VERIFY_DEPTH  | An integer value indicating the verification depth for the client certificate chain (Default: `1`) |
| WORKER_CONNECTIONS  | Maximum number of simultaneous connections that can be opened by a worker process (Default: `1024`) |

### Openresty ENV Variables

Openresty uses the same environment variables as the nginx version.

### ModSecurity ENV Variables

All these variables impact in configuration directives in the modsecurity engine running inside the container. The [reference manual](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)) has the extended documentation, and for your reference we list the specific directive we change when you modify the ENV variables for the container.

| Name     | Description|
| -------- | ------------------------------------------------------------------- |
| MODSEC_ARGUMENT_SEPARATOR | A character to use as the separator for `application/x-www-form-urlencoded` content. (Default: `&`). :warning: Do not touch unless you really know what you are doing. See [SecArgumentSeparator](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secargumentseparator) |
| MODSEC_ARGUMENTS_LIMIT | An integer indicating the maximum number of arguments that can be processed before setting the `REQBODY_ERROR` variable (Default `1000`). See [SecArgumentsLimit](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secargumentslimit)|
| MODSEC_AUDIT_ENGINE  | A string used to configure the audit engine, which logs complete transactions (Default: `RelevantOnly`). Accepted values: `On`, `Off`, `RelevantOnly`. See [SecAuditEngine](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#SecAuditEngine) for additional information. |
| 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`). Accepted values: `JSON`, `Native`. See [SecAuditLogFormat](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#SecAuditLogFormat) for additional information. |
| MODSEC_AUDIT_LOG_PARTS  | A string that defines which parts of each transaction are going to be recorded in the audit log (Default: `'ABIJDEFHZ'`). See [SecAuditLogParts](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secauditlogparts) for the accepted values. |
| MODSEC_AUDIT_LOG_RELEVANT_STATUS | A regular expression string that defines the http error codes that are relevant for audit logging (Default: `"^(?:5|4(?!04))"`). See [SecAuditLogRelevantStatus](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secauditlogrelevantstatus) |
| MODSEC_AUDIT_LOG_TYPE  | A string indicating the type of audit logging mechanism to be used (Default: `Serial`). Accepted values: `Serial`, `Concurrent` (`HTTPS` works only on Nginx - v3). See [SecAuditLogType](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secauditlogtype) for additional information. |
| MODSEC_COOKIE_FORMAT | The cookie format used (Default: `0` use Netscape cookies) :warning: Do not touch unless you really know what you are doing. See [SecCookieFormat](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#seccookieformat). |
| MODSEC_AUDIT_STORAGE_DIR  | 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`). Accepted values: `0` - `9`. See [SecDebugLogLevel](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secdebugloglevel). |
| MODSEC_DEFAULT_PHASE1_ACTION | ModSecurity string with the contents for the default action in phase 1 (Default: `'phase:1,log,auditlog,pass,tag:\'\${MODSEC_TAG}\''`) |
| MODSEC_DEFAULT_PHASE2_ACTION | ModSecurity string with the contents for the default action in phase 2 (Default: `'phase:2,log,auditlog,pass,tag:\'\${MODSEC_TAG}\''`) |
| MODSEC_DISABLE_BACKEND_COMPRESSION  | A string indicating whether or not to disable backend compression (Default: `On`). Allowed values: `On`, `Off`. See [SecDisableBackendCompression](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secdisablebackendcompression) for more. Only supported in ModSecurity 2.x, will have not effect on 3.x |
| MODSEC_PCRE_MATCH_LIMIT  | An integer value indicating the limit for the number of internal executions in the PCRE function (Default: `100000`) (Only valid for Apache - v2). See [SecPcreMatchLimit](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#SecPcreMatchLimit) |
| 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`). Allowed values: `On`, `Off`. See [SecRequestBodyAccess](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secrequestbodyaccess) for more information. |
| MODSEC_REQ_BODY_JSON_DEPTH_LIMIT | An integer value indicating the maximun JSON request depth (Default: `512`). See [SecRequestBodyJsonDepthLimit](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#SecRequestBodyJsonDepthLimit) for additional information. |
| MODSEC_REQ_BODY_LIMIT_ACTION  | A string value for the action when `SecRequestBodyLimit` is reached (Default: `Reject`). Accepted values: `Reject`, `ProcessPartial`. See [SecRequestBodyLimitAction](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secrequestbodylimitaction) for additional information. |
| MODSEC_REQ_BODY_LIMIT  | An integer value indicating the maximum request body size  accepted for buffering (Default: `13107200`). See [SecRequestBodyLimit](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secrequestbodylimit) for additional information. |
| MODSEC_REQ_BODY_NOFILES_LIMIT  | An integer indicating the maximum request body size ModSecurity will accept for buffering (Default: `131072`). See [SecRequestBodyNoFilesLimit](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secrequestbodynofileslimit) for more information. |
| MODSEC_RESP_BODY_ACCESS  | A string value allowing ModSecurity to access response bodies (Default: `On`). Allowed values: `On`, `Off`. See [SecResponseBodyAccess](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secresponsebodyaccess) for more information. |
| MODSEC_RESP_BODY_LIMIT_ACTION  | A string value for the action when `SecResponseBodyLimit` is reached (Default: `ProcessPartial`). Accepted values: `Reject`, `ProcessPartial`. See [SecResponseBodyLimitAction](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#secresponsebodylimitaction) for additional information. |
| MODSEC_RESP_BODY_LIMIT  | An integer value indicating the maximum response body size accepted for buffering (Default: `1048576`) |
| MODSEC_RESP_BODY_MIMETYPE  | A string with the list of mime types that will be analyzed in the response (Default: `'text/plain text/html text/xml'`). You might consider adding `application/json` documented [here](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-\(v2.x\)#secresponsebodymimetype). |
| MODSEC_RULE_ENGINE  | A string value enabling ModSecurity itself (Default: `On`). Accepted values: `On`, `Off`, `DetectionOnly`. See [SecRuleEngine](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secruleengine) for additional information. |
| MODSEC_SERVER_SIGNATURE  | Sets the directive [SecServerSignature](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secserversignature) and instructs ModSecurity to change the data presented in the "Server:" response header token when Apache `ServerTokens` directive is set to `Full`. Also see Apache `SERVER_TOKENS`. Only supported in ModSecurity 2.x, will have not effect on 3.x. (Default: `Apache`). |
| MODSEC_STATUS_ENGINE  | A string used to configure the status engine, which sends statistical information (Default: `Off`). Accepted values: `On`, `Off`. See [SecStatusEngine](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#SecStatusEngine) for additional information. |
| 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_TMP_SAVE_UPLOADED_FILES  | A string indicating if temporary uploaded files are saved (Default: `On`) (only relevant in Apache - ModSecurity v2) |
| MODSEC_UNICODE_MAPPING | The unicode Code Point to use form the default file(Default: `20127`). See [SecUnicodeMapFile](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secunicodemapfile) |
| MODSEC_UPLOAD_DIR  | A string indicating the path where intercepted files will be stored (Default: `/tmp/modsecurity/upload`) |
| MODSEC_UPLOAD_FILE_MODE | (Default: `0600`) |
| MODSEC_UPLOAD_KEEP_FILES | Configures whether or not the intercepted files will be kept after transaction is processed.  (Default: `RelevantOnly` on Apache, `Off` on nginx) Accepted values: `On`, `Off`, `RelevantOnly` (only modsec2). See [SecUploadKeepFiles](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v2.x%29#secuploadkeepfiles) and [libmodsecurity3](https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-%28v3.x%29#secuploadkeepfiles)

### CRS specific

| Name     | Description|
| -------- | ------------------------------------------------------------------- |
| ALLOWED_HTTP_VERSIONS | A string indicating the allowed_http_versions (Default: `HTTP/1.0 HTTP/1.1 HTTP/2 HTTP/2.0`) |
| 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\| \|multipart/related\| \|text/xml\| \|application/xml\| \|application/soap+xml\| \|application/json\| \|application/cloudevents+json\| \|application/cloudevents-batch+json\|`) |
| 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`) |
| ANOMALY_INBOUND | An integer indicating the inbound_anomaly_score_threshold (Default: `5`) |
| ANOMALY_OUTBOUND | An integer indicating the outbound_anomaly_score_threshold (Default: `4`) |
| ARG_LENGTH | An integer indicating the arg_length (Default: `unlimited`) |
| ARG_NAME_LENGTH | An integer indicating the arg_name_length (Default: `unlimited`) |
| BLOCKING_PARANOIA | (:new: Replaces `PARANOIA` in CRSv4) An integer indicating the paranoia level (Default: `1`)               |
| COMBINED_FILE_SIZES | An integer indicating the combined_file_sizes (Default: `unlimited`) |
| CRS_DISABLE_PLUGINS | A boolean indicating whether plugins will be **disabled** (Only from v4 and up. Default: `0`) |
| CRS_ENABLE_TEST_MARKER | A boolean indicating whether to write test markers to the log file (Used for running the CRS test suite. Default: `0`) |
| DETECTION_PARANOIA | (:new: Replaces `EXECUTING_PARANOIA` in CRSv4) An integer indicating the detection_paranoia_level (Default: `BLOCKING_PARANOIA`) |
| ENFORCE_BODYPROC_URLENCODED | A boolean indicating the enforce_bodyproc_urlencoded (Default: `0`) |
| EXECUTING_PARANOIA | An integer indicating the executing_paranoia_level (Default: `PARANOIA`) |
| MANUAL_MODE | A boolean indicating that you are providing your own `crs-setup.conf` file mounted as volume. (Default: `0`). ⚠️ None of the following variables are used if you set it to `1`. |
| MAX_FILE_SIZE | An integer indicating the max_file_size (Default: `unlimited`) |
| MAX_NUM_ARGS | An integer indicating the max_num_args (Default: `unlimited`) |
| PARANOIA | An integer indicating the paranoia level (Default: `1`)               |
| 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/ .rdb/ .resources/ .resx/ .sql/ .swp/ .sys/ .vb/ .vbs/ .vbproj/ .vsdisco/ .webinfo/ .xsd/ .xsx/`) |
| RESTRICTED_HEADERS_BASIC | A string indicating the restricted_headers_basic (Default: `/content-encoding/ /proxy/ /lock-token/ /content-range/ /if/ /x-http-method-override/ /x-http-method/ /x-method-override/`) |
| RESTRICTED_HEADERS_EXTENDED | A string indicating the restricted_headers_extended (Default: `/accept-charset/`) |
| STATIC_EXTENSIONS | A string indicating the static_extensions (Default: `/.jpg/ /.jpeg/ /.png/ /.gif/ /.js/ /.css/ /.ico/ /.svg/ /.webp/`) |
| TOTAL_ARG_LENGTH | An integer indicating the total_arg_length (Default: `unlimited`) |
| VALIDATE_UTF8_ENCODING | A boolean indicating the crs_validate_utf8_encoding (Default: `0`) |

## TLS/HTTPS

> [!IMPORTANT]  
> The default configuration generates a self signed certificate on first run. To use your own certificates (recommended) `COPY` or mount (`-v`) your `server.crt` and `server.key` into `/usr/local/apache2/conf/` or `/etc/nginx/conf/`. Remember to publish the HTTPS port when running the image.
>
> ```bash
> docker build -t my-modsec .
> docker run -p 8443:8443 my-modsec
> ```

TLS is configured on port `8443` and enabled by default.

We use sane intermediate defaults taken from the [Mozilla SSL config tool](https://ssl-config.mozilla.org/). Please review the defaults and choose the ones that best match your needs.

You can set the `*_ALWAYS_TLS_REDIRECT` environment variables to always redirect from `http` to `https`.

## Proxy Configuration

The owasp/modsecurity-crs container images in their default configuration (i.e., without manual changes to / overrides of configuration files) act as reverse proxies and require a running backend at the address specified through the `BACKEND` environment variable.

> [!IMPORTANT]
> Make sure to set the `BACKEND` variable to an address where a web server is listening. Otherwise nothing useful will happen when you send requests to the owasp/modsecurity-crs container (at least not with the default configurational).

ModSecurity is often used in a reverse proxy setup with the following porperties:
- reverse proxy acts as public end point
- reverse proxy performs TLS termination (necessary for ModSecurity to inspect content)
- ModSecurity runs on the reverse proxy to filter traffic
- only benign traffic is passed to the backend

This allows one to use ModSecurity without modifying the webserver hosting the underlying application and also protects web servers that ModSecurity cannot currently be embedd into.

Tips:
* the application web server (the one receiving traffic from the reverse proxy) should not listen on a public interface. Only the reverse proxy should be exposed to the public. With Docker, this could mean setting up a network for both containers and only exposing the reverse proxy with `-p 8080:8080`, for example. `docker compose` takes care of this automatically. See the `docker-compose.yaml` for an example setup.

```bash
docker build -t my-modsec . -f
docker run -p 8080:8080 -e BACKEND=http://example.com my-modsec
```

## ServerName

It is often convenient to set your server name (set to `localhost` by defualt). To do this simply use the `SERVER_NAME` environment variable.

```bash
docker build -t modsec .
docker run -p 8080:8080 -e SERVER_NAME=myhost my-modsec
```

## 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

```bash
docker run -dti --rm \
   -p 8080:8080 \
   -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:apache
```

### Copy ModSecurity tuning file into created container

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

```bash
docker create -ti --name modseccrs \
   -p 8080:8080 \
   owasp/modsecurity-crs:apache

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 of possible setup

The following example illustrates how to use `docker run` with some of the variables. It's purpose is illustration only and it should not be used to run a container in production.

Some important things to note:
- Error and audit logs are enabled and mapped to files on the host, so that their contents are accessible and don't pollute the container filesystem. Docker requires these files to exist, otherwise they would be created as directories, hence the use of the `touch ...` commands.
- For containers with read-only filesystems, the volumes might have to be specified differently, e.g., using `tmpfs`. Alternatively, if only one log output is required, the output could be redirected to `stdout` (`/proc/self/fd/2`).
- The example expects a backend web server to be running at `localhost:8081`.

```bash
touch /tmp/host-fs-auditlog.log
touch /tmp/host-fs-errorlog.log
docker run \
   -dti \
   -p 8080:8080 \
   --rm \
   -v /tmp/host-fs-auditlog.log:/var/log/modsec_audit.log \
   -v /tmp/host-fs-errorlog.log:/var/log/modsec_error.log \
   -e MODSEC_AUDIT_ENGINE=on \
   -e MODSEC_AUDIT_LOG=/var/log/modsec_audit.log
   -e LOGLEVEL=warn \
   -e ERRORLOG=/var/log/modsec_error.log \
   -e PARANOIA=1 \
   -e EXECUTING_PARANOIA=2 \
   -e ENFORCE_BODYPROC_URLENCODED=1 \
   -e ANOMALY_INBOUND=10 \
   -e ANOMALY_OUTBOUND=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 TIMEOUT=60 \
   -e SERVER_ADMIN=root@localhost \
   -e SERVER_NAME=localhost \
   -e PORT=8080 \
   -e MODSEC_RULE_ENGINE=on \
   -e MODSEC_REQ_BODY_ACCESS=on \
   -e MODSEC_REQ_BODY_LIMIT=13107200 \
   -e MODSEC_REQ_BODY_NOFILES_LIMIT=131072 \
   -e MODSEC_RESP_BODY_ACCESS=on \
   -e MODSEC_RESP_BODY_LIMIT=524288 \
   -e MODSEC_PCRE_MATCH_LIMIT=1000 \
   -e MODSEC_PCRE_MATCH_LIMIT_RECURSION=1000 \
   -e VALIDATE_UTF8_ENCODING=1 \
   -e CRS_ENABLE_TEST_MARKER=1 \
   -e BACKEND="http://localhost:8081" \
   owasp/modsecurity-crs:apache
```