NGINX App Protect DoS Release 4.1

Here you can find the release information for NGINX App Protect DoS v4.1. NGINX App Protect DoS provides behavioral protection against Denial of Service (DoS) for your web applications.

Release 4.1

May 2, 2023

In this release, NGINX App Protect DoS supports NGINX Plus R29.

New Features

  • Support for NGINX Plus R29
  • Support for Rocky Linux 8

Supported Packages

App Protect DoS

CentOS 7.4+ / RHEL 7.4+ / UBI7
  • app-protect-dos-29+4.1.2-1.el7.ngx.x86_64.rpm
RHEL 8 and Rocky Linux 8
  • app-protect-dos-29+4.1.2-1.el8.ngx.x86_64.rpm
Debian 11
  • app-protect-dos_29+4.1.2-1~bullseye_amd64.deb
Ubuntu 18.04
  • app-protect-dos_29+4.1.2-1~bionic_amd64.deb
Ubuntu 20.04
  • app-protect-dos_29+4.1.2-1~focal_amd64.deb
Alpine 3.15
  • app-protect-dos-


  • NGINX Plus R29

Important Notes

  • Installing L4 accelerated mitigation feature (install app-protect-dos-ebpf) configures nginx and admd to run with root privileges.

  • Support for proxy_protocol configuration: proxy_protocol monitor parameter should be used when the listen directive of the correspondent server block contains the proxy_protocol parameter.

  • If NGINX App Protect WAF is installed, app protect should be disabled for the location of DoS Live Activity Monitoring API.

    For example:

    location /api {
    app_protect_enable off;
  • Port configuration in app_protect_dos_monitor should correspond to the port, the server listens to. Misconfiguration can potentially cause a false attack declaration.

    For example:

        server {
            listen 8080;
            location / {  app_protect_dos_monitor "";  }
  • 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 the attack to 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.

  • Monitor directive app_protect_dos_monitor with proxy_protocol parameter can not be configured on Ubuntu 18.04. As a result, gRPC and HTTP/2 DoS protection for proxy_protocol configuration is not supported.

  • 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.

  • The package dependencies for NGINX App Protect DoS have changed in this release, replacing the curl dependencies with libcurl only. For more information, see the NGINX App Protect DoS Deployment Guide.