CVE-2013-1796 on Ubuntu 12.04 LTS (precise) - medium.
Description:
The kvm_set_msr_common function in arch/x86/kvm/x86.c in the Linux kernel through 3.8.4 does not ensure a required time_page alignment during an MSR_KVM_SYSTEM_TIME operation, which allows guest OS users to cause a denial of service (buffer overflow and host OS memory corruption) or possibly have unspecified other impact via a crafted application. Andrew Honig discovered a flaw in guest OS time updates in the Linux kernel's KVM (Kernel-based Virtual Machine). A privileged guest user could exploit this flaw to cause a denial of service (crash host system) or potential escalate privilege to the host kernel level.