A DoS can be caused by if a hacker exploits a vulnerability in Webwasher. This is due to a flaw in the processing of URLs running on the newer Linux system. It can be exploited to freeze the service by processing a carefully crafted URL.

Affected applications are Webwashwer appliances 6.x (CGLinux 4 or 5) prior to build number 3150, and Webwasher software versions prior to versions 6.6.3 build 3150 or 5.3.0 build 3159 running on: RedHat Enterprise Linux 4, Debian Linux 4, and SLES 10.

A solution is to update to versions 6.6.3 build 3150 or 5.3.0 build 3159: https://extranet.webwasher.com/download/csm/index.html

This vulnerability was discovered by the National Australia Bank Security Assurance.

REFERENCES:
Secunia
Webwasher URL Processing Denial of Service Vulnerability