Scientific Linux Security Update : kvm on SL5.x x86_64

This script is Copyright (C) 2012-2013 Tenable Network Security, Inc.


Synopsis :

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

Description :

It was found that QEMU-KVM on the host did not validate all pointers
provided from a guest system's QXL graphics card driver. A privileged
guest user could use this flaw to cause the host to dereference an
invalid pointer, causing the guest to crash (denial of service) or,
possibly, resulting in the privileged guest user escalating their
privileges on the host. (CVE-2010-0431)

A flaw was found in QEMU-KVM, allowing the guest some control over the
index used to access the callback array during sub-page MMIO
initialization. A privileged guest user could use this flaw to crash
the guest (denial of service) or, possibly, escalate their privileges
on the host. (CVE-2010-2784)

A NULL pointer dereference flaw was found when the host system had a
processor with the Intel VT-x extension enabled. A privileged guest
user could use this flaw to trick the host into emulating a certain
instruction, which could crash the host (denial of service).
(CVE-2010-0435)

This update also fixes the following bugs :

- running a 'qemu-img' check on a faulty virtual machine
image ended with a segmentation fault. With this update,
the segmentation fault no longer occurs when running the
'qemu-img' check. (BZ#610342)

- when attempting to transfer a file between two guests
that were joined in the same virtual LAN (VLAN), the
receiving guest unexpectedly quit. With this update, the
transfer completes successfully. (BZ#610343)

- installation of a system was occasionally failing in
KVM. This was caused by KVM using wrong permissions for
large guest pages. With this update, the installation
completes successfully. (BZ#616796)

- previously, the migration process would fail for a
virtual machine because the virtual machine could not
map all the memory. This was caused by a conflict that
was initiated when a virtual machine was initially run
and then migrated right away. With this update, the
conflict no longer occurs and the migration process no
longer fails. (BZ#618205)

- using a thinly provisioned VirtIO disk on iSCSI storage
and performing a 'qemu-img' check during an 'e_no_space'
event returned cluster errors. With this update, the
errors no longer appear. (BZ#618206)

NOTE: 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.

See also :

http://www.nessus.org/u?fd19f1a8
https://bugzilla.redhat.com/show_bug.cgi?id=610342
https://bugzilla.redhat.com/show_bug.cgi?id=610343
https://bugzilla.redhat.com/show_bug.cgi?id=616796
https://bugzilla.redhat.com/show_bug.cgi?id=618205
https://bugzilla.redhat.com/show_bug.cgi?id=618206

Solution :

Update the affected packages.

Risk factor :

Medium / CVSS Base Score : 6.6
(CVSS2#AV:L/AC:M/Au:S/C:C/I:C/A:C)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 60837 ()

Bugtraq ID:

CVE ID: CVE-2010-0431
CVE-2010-0435
CVE-2010-2784