The Datadog nginx tracing module has experimental support for threat detection and blocking.

Enabling threat detection

Get started

1. Verify that your nginx build was compiled with the flag --with-threads. Most distributions ship with this flag enabled by default. To check if your nginx installation was built with thread support, run nginx -V and check the configure arguments line. If you cannot find --with-threads in the output, you will need to rebuild nginx with this flag enabled. For more information on how to build nginx from sources, see the nginx documentation.

2. Update your nginx tracing library module to at least version 1.2.0. Visit the GitHub releases page and select the artifact named according to the pattern “ngx_http_datadog_module-appsec-<amd64/arm64>-<nginx version>.so.tgz”. Note that this artifact includes “appsec” in the name.

3. Enable ASM in the nginx configuration. You need to:

   • define one or more thread pools with the thread_pool directive,
   • explicitly enable AppSec with datadog_appsec_enabled, and
   • map requests to a thread pool or pools that you defined with the directive datadog_waf_thread_pool_name.

   For example:

   load_module /path/to/ngx_http_datadog_module.so;
   thread_pool waf_thread_pool threads=4 max_queue=128;
   http {
     datadog_appsec_enabled on;
     datadog_waf_thread_pool_name waf_thread_pool;
   }
   

   For more information, see the reference documentation.

   After this configuration is complete, the library collects security data from your application and sends it to the Agent, which sends it to Datadog, where out-of-the-box detection rules flag attacker techniques and potential misconfigurations so you can take steps to remediate.

4. To see Application Security Management threat detection in action, send known attack patterns to your application. For example, trigger the Security Scanner Detected rule by running a file that contains the following curl script:

   for ((i=1;i<=250;i++)); 
   do
   # Target existing service’s routes
   curl https://your-application-url/existing-route -A dd-test-scanner-log;
   # Target non existing service’s routes
   curl https://your-application-url/non-existing-route -A dd-test-scanner-log;
   done

   Note: The dd-test-scanner-log value is supported in the most recent releases.

   A few minutes after you enable your application and exercise it, threat information appears in the Application Signals Explorer and vulnerability information appears in the Vulnerability Explorer.

Limitations

As of version 1.2.0, the available functionality has the following important limitations:

• The request body is not inspected, regardless of its content type.

• There is no remote configuration for AppSec. Consequently, AppSec excludes 1-click activation (AppSec must be explicitly enabled or disabled in the nginx configuration), rules cannot be updated/enabled/disabled, and blocking users by IP address is prevented, since the list cannot be transmitted to the nginx module.

• It’s not possible to block the request based on characteristics of the response, such as its status code, headers, or body.

Further Reading

Additional helpful documentation, links, and articles:

nginx integration's source codeSOURCE CODE OOTB Application Security Management RulesDOCUMENTATION Troubleshooting Application Security ManagementDOCUMENTATION