NGINX App Protect DoS Release 3.1

Here you can find the release information for NGINX App Protect DoS v3.1. NGINX App Protect DoS provides behavioral protection against Denial of Service (DoS) for your web applications.

Release 3.1

November 29, 2022

In this release, NGINX App Protect DoS supports NGINX Plus R28.

New Features

  • Support for NGINX Plus R28.
  • NGINX App protect DoS can be deployed behind L4/L7 load balancers when L4 protection is enabled.
  • Fixed the issue: Installing NGINX App protect DoS with L4 (eBPF) mitigation behind L4/L7 load balancer may result in the load balancer’s starvation during an attack.
  • Support for proxy_protocol configuration for server health monitoring.
    Previously, server health monitoring could not be used when the listen directive of the correspondent server block contained the proxy_protocol parameter.
    This disallowed using NGINX App protect DoS for Denial of Service (DoS) protection for HTTP2 and gRPC protected objects in the proxy_protocol configuration.

Supported Packages

App Protect DoS

CentOS 7.4+ / RHEL 7.4+ / UBI7
  • app-protect-dos-28+3.1.7-1.el7.ngx.x86_64.rpm
  • app-protect-dos-28+3.1.7-1.el8.ngx.x86_64.rpm
Debian 11
  • app-protect-dos_28+3.1.7-1~bullseye_amd64.deb
Ubuntu 18.04
  • app-protect-dos_28+3.1.7-1~bionic_amd64.deb
Ubuntu 20.04
  • app-protect-dos_28+3.1.7-1~focal_amd64.deb
Alpine 3.15
  • app-protect-dos-


  • NGINX Plus R28

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;
  • 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 "";  }
  • 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.

  • Monitor directive (app_protect_monitor) with the 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.