The remote host is missing an update to crossfire announced via advisory DSA 1001-1. It was discovered that Crossfire, a multiplayer adventure game, performs insufficient bounds checking on network packets when run in oldsocketmode, which may possibly lead to the execution of arbitrary code. For the old stable distribution (woody) this problem has been fixed in version 1.1.0-1woody1.
For the stable distribution (sarge) this problem has been fixed in version 1.6.0.dfsg.1-4sarge1. For the unstable distribution (sid) this problem has been fixed in version 1.9.0-1. We recommend that you upgrade your crossfire packages. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201001-1