The remote host is missing an update to kvm announced via advisory DSA 1846-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201846-1

Matt T. Yourst discovered an issue in the kvm subsystem. Local users with permission to manipulate /dev/kvm can cause a denial of service (hang) by providing an invalid cr3 value to the KVM_SET_SREGS call. For the stable distribution (lenny), these problems have been fixed in version 72+dfsg-5~lenny2. For the unstable distribution (sid), these problems will be fixed soon. We recommend that you upgrade your kvm packages, and rebuild any kernel