NGINX App Protect DoS Release 2.2

Here you can find the release information for NGINX App Protect DoS v2.2. NGINX App Protect DoS provides behavioral protection against Denial of Service (DoS) for your web applications.

Release 2.2

February 15, 2022

In this release, support for NGINX App Protect DoS is added to NGINX Plus R26.

New Features

  • Improve Signature Lifecycle

Supported Packages

App Protect DoS

CentOS 7.4+ / RHEL 7.4+ / UBI7
  • app-protect-dos-26+2.2.20-1.el7.ngx.el7.ngx.x86_64.rpm
  • app-protect-dos-26+2.2.20-1.el8.ngx.el8.ngx.x86_64.rpm
Debian 10
  • app-protect-dos_26+2.2.20-1~buster_amd64.deb
Ubuntu 18.04
  • app-protect-dos_26+2.2.20-1~bionic_amd64.deb
Ubuntu 20.04
  • app-protect-dos_26+2.2.20-1~focal_amd64.deb


  • NGINX Plus R26

Resolved Issues

  • Monitor requests are sent in new connections. It improves monitoring health capability and allows better detection of slow POST attacks.

  • Adaptive memory allocation by adminstall in order to support maximum cores. The amount of allocated memory for NGINX App Protect DoS is controlled by an argument of adminstall. The default value is 80 MB. For certain deployments, this amount of memory size is not enough. The default memory size is adaptive now. If the Virtual Machine (VM) has a big number of CPU cores, then we can also increase the amount of memory. For the case of up to 4 CPU cores, the allocated memory is 80MB, for more than 4 CPU cores, the allocated memory will be calculated as 80MB + CPUs * 2.5MB

Important Notes

  • Misconfiguration of app_protect_dos_monitor 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.

  • 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.