The remote host is missing an update to nis announced via advisory DSA 180-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20180-1

Thorsten Kukuck discovered a problem in the ypserv program which is part of the Network Information Services (NIS). A memory leak in all versions of ypserv prior to 2.5 is remotely exploitable. When a malicious user could request a non-existing map the server will leak parts of an old domainname and mapname. This problem has been fixed in version 3.9-6.1 for the current stable distribution (woody), in version 3.8-2.1 for the old stable distribution (potato) and in version 3.9-6.2 for the unstable distribution (sid). We recommend that you upgrade your nis package.