The remote host is missing an update to kdm (kdebase) announced via advisory DSA 2037-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202037-1

Sebastian Krahmer discovered that a race condition in the KDE Desktop Environment's KDM display manager, allow a local user to elevate privileges to root. For the stable distribution (lenny), this problem has been fixed in version 4:3.5.9.dfsg.1-6+lenny1. For the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your kdm package.