The remote host is missing an update to freesweep announced via advisory DSA 391-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20391-1

Steve Kemp discovered a buffer overflow in freesweep, when processing several environment variables. This vulnerability could be exploited by a local user to gain gid 'games'. For the current stable distribution (woody) this problem has been fixed in version 0.88-4woody1. For the unstable distribution (sid) this problem will be fixed soon. We recommend that you update your freesweep package.