Scientific Linux Security Update : qemu-kvm on SL6.x x86_64 (20120905)

high Nessus Plugin ID 61795

Synopsis

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

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 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.

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.

To resolve dependency issues, the usbredir packages have been added to the repos.

Solution

Update the affected packages.

See Also

http://www.nessus.org/u?e7342cc9

Plugin Details

Severity: High

ID: 61795

File Name: sl_20120905_qemu_kvm_on_SL6_x.nasl

Version: 1.7

Type: local

Agent: unix

Published: 9/6/2012

Updated: 1/14/2021

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Vulnerability Information

CPE: p-cpe:/a:fermilab:scientific_linux:qemu-guest-agent, p-cpe:/a:fermilab:scientific_linux:qemu-kvm-tools, x-cpe:/o:fermilab:scientific_linux, p-cpe:/a:fermilab:scientific_linux:qemu-img, p-cpe:/a:fermilab:scientific_linux:qemu-kvm

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/RedHat/release, Host/RedHat/rpm-list

Patch Publication Date: 9/5/2012

Vulnerability Publication Date: 11/23/2012

Reference Information

CVE: CVE-2012-3515