Oracle Linux 6 : qemu-kvm (ELSA-2012-1234)

This script is Copyright (C) 2013 Tenable Network Security, Inc.


Synopsis :

The remote Oracle Linux host is missing one or more security updates.

Description :

From Red Hat Security Advisory 2012:1234 :

Updated qemu-kvm packages that fix one security issue are now
available for Red Hat Enterprise Linux 6.

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.

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 handled VT100 terminal escape
sequences when emulating certain character devices. A guest user with
privileges to write to a character device that is emulated on the host
using a virtual console back-end could use this flaw to crash the
qemu-kvm process on the host or, possibly, escalate their privileges
on the host. (CVE-2012-3515)

This flaw did not affect the default use of KVM. Affected
configurations were :

* When guests were started from the command line
('/usr/libexec/qemu-kvm') without the '-nodefaults' option, and also
without specifying a serial or parallel device, or a virtio-console
device, that specifically does not use a virtual console (vc)
back-end. (Note that Red Hat does not support invoking 'qemu-kvm' from
the command line without '-nodefaults' on Red Hat Enterprise Linux 6.)

* Guests that were managed via libvirt, such as when using Virtual
Machine Manager (virt-manager), but that have a serial or parallel
device, or a virtio-console device, that uses a virtual console
back-end. By default, guests managed via libvirt will not use a
virtual console back-end for such devices.

Red Hat would like to thank the Xen project for reporting this issue.

All users of qemu-kvm should upgrade to these updated packages, which
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.

See also :

https://oss.oracle.com/pipermail/el-errata/2012-September/003011.html

Solution :

Update the affected qemu-kvm packages.

Risk factor :

High / CVSS Base Score : 7.2
(CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C)
CVSS Temporal Score : 6.3
(CVSS2#E:ND/RL:OF/RC:C)
Public Exploit Available : false

Family: Oracle Linux Local Security Checks

Nessus Plugin ID: 68612 ()

Bugtraq ID: 55413

CVE ID: CVE-2012-3515