Scientific Linux Security Update : qemu-kvm on SL6.x x86_64
Medium Nessus Plugin ID 61195
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionKVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component for running virtual machines using KVM.
It was found that qemu-kvm did not properly drop supplemental group privileges when the root user started guests from the command line ('/usr/libexec/qemu-kvm') with the '-runas' option. A qemu-kvm process started this way could use this flaw to gain access to files on the host that are accessible to the supplementary groups and not accessible to the primary group. (CVE-2011-2527)
Note: This issue only affected qemu-kvm when it was started directly from the command line. It did not affect applications that start qemu-kvm via libvirt, such as the Virtual Machine Manager (virt-manager).
A flaw was found in the way qemu-kvm handled VSC_ATR messages when a guest was configured for a CCID (Chip/Smart Card Interface Devices) USB smart card reader in passthrough mode. An attacker able to connect to the port on the host being used for such a device could use this flaw to crash the qemu-kvm process on the host or, possibly, escalate their privileges on the host. (CVE-2011-4111)
All users of qemu-kvm should upgrade to these updated packages, which contain a backported patch to resolve this issue. After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.
A number of additional packages were added to the security repository so that this package could be installed on older SL systems.
SolutionUpdate the affected packages.