The remote host is missing an update to heimdal announced via advisory DSA 185-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20185-1

A stack buffer overflow in the kadm_ser_wrap_in function in the Kerberos v4 administration server was discovered, which is provided by Heimdal as well. A working exploit for this kadmind bug is already circulating, hence it is considered serious. The roken library also contains a vulnerability which could lead to another root exploit. These problems have been fixed in version 0.4e-7.woody.5 for the current stable distribution (woody), in version 0.2l-7.6 for the old stable distribution (potato) and in version 0.4e-22 for the unstable distribution (sid). We recommend that you upgrade your heimdal packages immediately.