'ypupdated -i' is running on this port. Description : ypupdated is part of NIS and allows a client to update NIS maps. This old command execution vulnerability was discovered in 1995 and fixed then. However, it is still possible to run ypupdated in insecure mode by adding the '-i' option. Anybody can easily run commands as root on this machine by specifying an invalid map name that starts with a pipe character. Exploits have been publicly available since the first advisory.
Remove the '-i' option. If this option was not set, the rpc.ypupdated daemon is still vulnerable to the old flaw contact your vendor for a patch.