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

High Nessus Plugin ID 60515


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


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.

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.


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

See Also

Plugin Details

Severity: High

ID: 60515

File Name: sl_20090107_xen_on_SL5_x.nasl

Version: $Revision: 1.2 $

Type: local

Agent: unix

Published: 2012/08/01

Modified: 2016/12/14

Dependencies: 12634

Risk Information

Risk Factor: High


Base Score: 7.2

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

Vulnerability Information

CPE: x-cpe:/o:fermilab:scientific_linux

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

Patch Publication Date: 2009/01/07

Reference Information

CVE: CVE-2008-4405, CVE-2008-4993

CWE: 59, 264