Skip to navigation

Security Advisory Important: kvm security update

Advisory: RHSA-2012:1235-1
Type: Security Advisory
Severity: Important
Issued on: 2012-09-05
Last updated on: 2012-09-05
Affected Products: RHEL Desktop Multi OS (v. 5 client)
RHEL Virtualization (v. 5 server)
CVEs (cve.mitre.org): CVE-2012-3515

Details

Updated kvm packages that fix one security issue are now available for
Red Hat Enterprise Linux 5.

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. KVM is a Linux kernel module built
for the standard Red Hat Enterprise Linux kernel.

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"),
and without specifying a serial or parallel 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 on Red Hat Enterprise
Linux 5.)

* Guests that were managed via libvirt, such as when using Virtual Machine
Manager (virt-manager), but that have a serial or parallel 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 KVM users should upgrade to these updated packages, which correct this
issue. Note: The procedure in the Solution section must be performed before
this update will 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/knowledge/articles/11258

The following procedure must be performed before this update will take
effect:

1) Stop all KVM guest virtual machines.

2) Either reboot the hypervisor machine or, as the root user, remove (using
"modprobe -r [module]") and reload (using "modprobe [module]") all of the
following modules which are currently running (determined using "lsmod"):
kvm, ksm, kvm-intel or kvm-amd.

3) Restart the KVM guest virtual machines.

Updated packages

RHEL Desktop Multi OS (v. 5 client)

SRPMS:
kvm-83-249.el5_8.5.src.rpm
File outdated by:  RHSA-2014:0163
    MD5: 73185a9f5e156132ec8b7e33af3c7ad2
SHA-256: 3c4ab02763d01cf0e0517e0bdc05ec4c19f061c143c4e048560be4d42221d8f8
 
x86_64:
kmod-kvm-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: df321d97cfcd1f84248a6e5afb6dddbe
SHA-256: 70de6afc34d5f6f0a4e8dd0115b5245061ee0b1bb35b92f209f83dcbfcc0744e
kmod-kvm-debug-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 5fa002b215c5dc08c927fcb764d1e2cf
SHA-256: 096b37e4252c02a931c213cd53a17097bf299cd6308af8ac56460a90d3153928
kvm-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 1dfa0ebaf1cee9c2d1119317d0bd70ef
SHA-256: 2caaeb74effae1230fffbdd7a87834dde571edf44764ce871ab12d523e92821e
kvm-debuginfo-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 22f85adb3f22a9358fc2ba78431aba9b
SHA-256: ae8928b078c29b70d9f2294e97584e9a20a6c7f696dbe096b5703488bba66f02
kvm-qemu-img-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: d51d79352ed148eb828383487aa25eba
SHA-256: 0ebabb804a17e1dd9f56ce8b557d93b01ef9cc8fb761d849f211f81d618f31c6
kvm-tools-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: de83eea909b77201c4fa0dadfe45b1e5
SHA-256: fe0bb79e75cf65ed623cea0c52288b59f0e347c94446d4ab6a94f35c42a0c4e9
 
RHEL Virtualization (v. 5 server)

SRPMS:
kvm-83-249.el5_8.5.src.rpm
File outdated by:  RHSA-2014:0163
    MD5: 73185a9f5e156132ec8b7e33af3c7ad2
SHA-256: 3c4ab02763d01cf0e0517e0bdc05ec4c19f061c143c4e048560be4d42221d8f8
 
x86_64:
kmod-kvm-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: df321d97cfcd1f84248a6e5afb6dddbe
SHA-256: 70de6afc34d5f6f0a4e8dd0115b5245061ee0b1bb35b92f209f83dcbfcc0744e
kmod-kvm-debug-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 5fa002b215c5dc08c927fcb764d1e2cf
SHA-256: 096b37e4252c02a931c213cd53a17097bf299cd6308af8ac56460a90d3153928
kvm-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 1dfa0ebaf1cee9c2d1119317d0bd70ef
SHA-256: 2caaeb74effae1230fffbdd7a87834dde571edf44764ce871ab12d523e92821e
kvm-debuginfo-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 22f85adb3f22a9358fc2ba78431aba9b
SHA-256: ae8928b078c29b70d9f2294e97584e9a20a6c7f696dbe096b5703488bba66f02
kvm-qemu-img-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: d51d79352ed148eb828383487aa25eba
SHA-256: 0ebabb804a17e1dd9f56ce8b557d93b01ef9cc8fb761d849f211f81d618f31c6
kvm-tools-83-249.el5_8.5.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: de83eea909b77201c4fa0dadfe45b1e5
SHA-256: fe0bb79e75cf65ed623cea0c52288b59f0e347c94446d4ab6a94f35c42a0c4e9
 
(The unlinked packages above are only available from the Red Hat Network)

Bugs fixed (see bugzilla for more information)

851252 - CVE-2012-3515 qemu: VT100 emulation vulnerability


References



These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from:
https://www.redhat.com/security/team/key/#package

The Red Hat security contact is secalert@redhat.com. More contact details at http://www.redhat.com/security/team/contact/