Scientific Linux Security Update : xen on SL5.x i386/x86_64

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


Synopsis :

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

Description :

Xen was found to allow unprivileged DomU domains to overwrite xenstore
values which should only be changeable by the privileged Dom0 domain.
An attacker controlling a DomU domain could, potentially, use this
flaw to kill arbitrary processes in Dom0 or trick a Dom0 user into
accessing the text console of a different domain running on the same
host. This update makes certain parts of the xenstore tree read-only
to the unprivileged DomU domains. (CVE-2008-4405)

It was discovered that the qemu-dm.debug script created a temporary
file in /tmp in an insecure way. A local attacker in Dom0 could,
potentially, use this flaw to overwrite arbitrary files via a symlink
attack. Note: This script is not needed in production deployments and
therefore was removed and is not shipped with updated xen packages.
(CVE-2008-4993)

This update also fixes the following bug :

- xen calculates its running time by adding the
hypervisor's up-time to the hypervisor's boot-time
record. In live migrations of para-virtualized guests,
however, the guest would over-write the new hypervisor's
boot-time record with the boot-time of the previous
hypervisor. This caused time-dependent processes on the
guests to fail (for example, crond would fail to start
cron jobs). With this update, the new hypervisor's
boot-time record is no longer over-written during live
migrations.

The Xen host must be restarted for the update to take effect.

See also :

http://www.nessus.org/u?fca6725a

Solution :

Update the affected xen, xen-devel and / or xen-libs packages.

Risk factor :

High / CVSS Base Score : 7.2
(CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 60515 ()

Bugtraq ID:

CVE ID: CVE-2008-4405
CVE-2008-4993