Multiple methods in libvirt 0.3.2 through 0.5.1 do not check if a connection is read-only, which allows local users to bypass intended access restrictions and perform administrative actions.

From Red Hat Security Advisory 2009:0382 :

Updated libvirt packages that fix two security issues are now available for Red Hat Enterprise Linux 5.

This update has been rated as having moderate security impact by the Red Hat Security Response Team.

[Updated 5th May 2011] After installing this update and restarting the libvirtd service, the 'virsh attach-disk' command failed. Rebooting guest systems after installing the update resolved the issue. The erratum text has been updated to reflect that guest systems must be rebooted. Future updates will advise if a guest reboot is needed. No changes have been made to the packages.

libvirt is a C API for managing and interacting with the virtualization capabilities of Linux and other operating systems.
libvirt also provides tools for remotely managing virtualized systems.

The libvirtd daemon was discovered to not properly check user connection permissions before performing certain privileged actions, such as requesting migration of an unprivileged guest domain to another system. A local user able to establish a read-only connection to libvirtd could use this flaw to perform actions that should be restricted to read-write connections. (CVE-2008-5086)

libvirt_proxy, a setuid helper application allowing non-privileged users to communicate with the hypervisor, was discovered to not properly validate user requests. Local users could use this flaw to cause a stack-based buffer overflow in libvirt_proxy, possibly allowing them to run arbitrary code with root privileges.
(CVE-2009-0036)

All users are advised to upgrade to these updated packages, which contain backported patches which resolve these issues. After installing the update, libvirtd must be restarted manually (for example, by issuing a 'service libvirtd restart' command), and guest systems rebooted, for this change to take effect.

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2009:0382 advisory.

  - libvirt: missing checks for read-only connection (CVE-2008-5086)

  - libvirt: libvirt_proxy buffer overflow (CVE-2009-0036)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The libvirtd daemon was discovered to not properly check user connection permissions before performing certain privileged actions, such as requesting migration of an unprivileged guest domain to another system. A local user able to establish a read-only connection to libvirtd could use this flaw to perform actions that should be restricted to read-write connections. (CVE-2008-5086)

libvirt_proxy, a setuid helper application allowing non-privileged users to communicate with the hypervisor, was discovered to not properly validate user requests. Local users could use this flaw to cause a stack-based buffer overflow in libvirt_proxy, possibly allowing them to run arbitrary code with root privileges.
(CVE-2009-0036)

After installing the update, libvirtd must be restarted manually (for example, by issuing a 'service libvirtd restart' command) for this change to take effect.

libvirt misses some read-only connection checks for certain methods.
This flaw enables local unprivileged users for example to migrate virtual machines without authentication. (CVE-2008-5086)

libvirt misses some read-only connection checks for certain methods.
This flaw enables local unprivileged users for example to migrate virtual machines without authentication (CVE-2008-5086).

It was discovered that libvirt did not mark certain operations as read-only. A local attacker may be able to perform privileged actions such as migrating virtual machines, adjusting autostart flags, or accessing privileged data in the virtual machine memory and disks.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

fix missing read-only access checks, fixes CVE-2008-5086 - upstream release 0.5.1 - mostly bugfixes e.g #473071 - some driver improvements

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
67832	Oracle Linux 5 : libvirt (ELSA-2009-0382)	Nessus	Oracle Linux Local Security Checks	high
63878	RHEL 5 : libvirt (RHSA-2009:0382)	Nessus	Red Hat Local Security Checks	critical
60551	Scientific Linux Security Update : libvirt on SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	high
41554	SuSE 10 Security Update : libvirt (ZYPP Patch Number 5869)	Nessus	SuSE Local Security Checks	high
40272	openSUSE Security Update : libvirt (libvirt-373)	Nessus	SuSE Local Security Checks	high
40051	openSUSE Security Update : libvirt (libvirt-373)	Nessus	SuSE Local Security Checks	high
37984	Ubuntu 7.10 / 8.04 LTS / 8.10 : libvirt vulnerability (USN-694-1)	Nessus	Ubuntu Local Security Checks	high
36460	Fedora 10 : libvirt-0.5.1-2.fc10 (2008-11443)	Nessus	Fedora Local Security Checks	high
35607	openSUSE 10 Security Update : libvirt (libvirt-5874)	Nessus	SuSE Local Security Checks	high
35228	Fedora 9 : libvirt-0.5.1-2.fc9 (2008-11433)	Nessus	Fedora Local Security Checks	high

Detections

Analytics

CVE-2008-5086

high

Tenable Plugins

high

critical

high

high

high

high

high

high

high

high