VCST-67-000002 - The Security Token Service must limit the number of concurrent connections permitted.


Resource exhaustion can occur when an unlimited number of concurrent requests are allowed on a website, facilitating a denial-of-service attack. Unless the number of requests is controlled, the web server can consume enough system resources to cause a system crash.

Mitigating this kind of attack will include limiting the number of concurrent HTTP/HTTPS requests. In Tomcat, each incoming request requires a thread for the duration of that request. If more simultaneous requests are received than can be handled by the currently available request processing threads, additional threads will be created up to the value of the 'maxThreads' attribute.


Navigate to and open /usr/lib/vmware-sso/vmware-sts/conf/server.xml.

Navigate to the mode with the name of 'tomcatThreadPool' and configure with the value:


Note: The node should be configured as follows:

Supportive Information

The following resource is also helpful.

This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system Unix.