RHSA-2011:1801 - Security Advisory

Topic

Updated qemu-kvm packages that fix one security issue are now available for
Red Hat Enterprise Linux 6.1 Extended Update Support.

The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link in the References section.

Description

KVM (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.

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.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 x86_64
• Red Hat Virtual Storage Appliance (from RHUI) 6.1 x86_64

Fixes

• BZ - 751310 - CVE-2011-4111 qemu: ccid: buffer overflow in handling of VSC_ATR message

CVEs

• CVE-2011-4111

References

• https://access.redhat.com/security/updates/classification/#important