The remote host is missing an update to glibc, eglibc announced via advisory DSA 1973-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201973-1

Christoph Pleger has discovered that the GNU C Library (aka glibc) and its derivatives add information from the passwd.adjunct.byname map to entries in the passwd map, which allows local users to obtain the encrypted passwords of NIS accounts by calling the getpwnam function. For the oldstable distribution (etch), this problem has been fixed in version 2.3.6.ds1-13etch10 of the glibc package. For the stable distribution (lenny), this problem has been fixed in version 2.7-18lenny2 of the glibc package. For the unstable distribution (sid) this problem has been fixed in version 2.10.2-4 of the eglibc package. We recommend that you upgrade your glibc or eglibc package.