NGINX App Protect DoS Release 2.3

Here you can find the release information for NGINX App Protect DoS v2.3. NGINX App Protect DoS provides behavioral protection against Denial of Service (DoS) for your web applications.

Release 2.3

May 9, 2022

New Features

Supported Packages

App Protect DoS

CentOS 7.4+ / RHEL 7.4+ / UBI7
  • app-protect-dos-26+2.3.46-1.el7.ngx.el7.ngx.x86_64.rpm
  • app-protect-dos-26+2.3.46-1.el8.ngx.el8.ngx.x86_64.rpm
Debian 10
  • app-protect-dos_26+2.3.46-1~buster_amd64.deb
Ubuntu 18.04
  • app-protect-dos_26+2.3.46-1~bionic_amd64.deb
Ubuntu 20.04
  • app-protect-dos_26+2.3.46-1~focal_amd64.deb
Alpine 3.15
  • app-protect-dos-


  • NGINX Plus R26

Resolved Issues

  • Improved Security logger configuration parsing: Detects invalid JSON structure, generates an appropriate message if field/value is not valid, doesn’t stop on the first failure.

Important Notes

  • Misconfiguration of app_protect_dos_monitor potentially can cause a false attack declaration. Port configuration should correspond to the port the server listens to.

    For example:

        server {
            listen 8080;
            location / {  app_protect_dos_monitor "";  }

Please note that the above syntax for the Monitor directive is old but still supported.

The new syntax for the Monitor directive is as stated below, where protocol and timeout arguments are optional and default. Refer to Learn about Directives and Policy for more details on Monitor directive new syntax.

For example:

app_protect_dos_monitor protocol=http1 timeout=5;

  • proxy_request_buffering off is not supported.

  • gRPC and HTTP/2 protection require active monitoring of the protected service. The directive app_protect_dos_monitor is mandatory for these use cases, otherwise, the attack will not be detected.

  • TLS fingerprint feature is not used in CentOS 7.4 and RHEL 7/UBI 7 due to the old OpenSSL version. The required OpenSSL version is 1.1.1 or higher.

  • Slow POST attack always mitigates with block action while other types of attacks can also be mitigated with redirection or JS challenges.

  • The recommended option of running NGINX Plus in a Docker Container is with the daemon off flag. It’s mandatory for UBI 8.