source: https://www.securityfocus.com/bid/6228/info

Rational ClearCase has been reported to be prone to a denial of service condition. It is possible to cause this condition by portscanning a system running the vulnerable version of ClearCase. This issue was demonstrated using the nmap portscanning utility.

An attacker can exploit this vulnerability by making two consecutive portscans of a vulnerable system. This will cause ClearCase to crash. Restarting the ClearCase service is required to restore functionality.

nmap -vvv -O -sT ip.of.clearcase.system
nmap -vvv -O -sT -p 371 ip.of.clearcase.system