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Security Advisory Low: libvirt security and bug fix update

Advisory: RHSA-2010:0615-1
Type: Security Advisory
Severity: Low
Issued on: 2010-08-10
Last updated on: 2010-08-10
Affected Products: RHEL Desktop Multi OS (v. 5 client)
RHEL Virtualization (v. 5 server)
CVEs (cve.mitre.org): CVE-2010-2239
CVE-2010-2242

Details

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

The Red Hat Security Response Team has rated this update as having low
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

The libvirt library is a C API for managing and interacting with the
virtualization capabilities of Linux and other operating systems. In
addition, libvirt provides tools for remotely managing virtualized systems.

It was found that libvirt did not set the user-defined backing store format
when creating a new image, possibly resulting in applications having to
probe the backing store to discover the format. A privileged guest user
could use this flaw to read arbitrary files on the host. (CVE-2010-2239)

It was found that libvirt created insecure iptables rules on the host when
a guest system was configured for IP masquerading, allowing the guest to
use privileged ports on the host when accessing network resources. A
privileged guest user could use this flaw to access network resources that
would otherwise not be accessible to the guest. (CVE-2010-2242)

Red Hat would like to thank Jeremy Nickurak for reporting the CVE-2010-2242
issue.

This update also fixes the following bugs:

* a Linux software bridge assumes the MAC address of the enslaved interface
with the numerically lowest MAC address. When the bridge changes its MAC
address, for a period of time it does not relay packets across network
segments, resulting in a temporary network "blackout". The bridge should
thus avoid changing its MAC address in order not to disrupt network
communications.

The Linux kernel assigns network TAP devices a random MAC address.
Occasionally, this random MAC address is lower than that of the physical
interface which is enslaved (for example, eth0 or eth1), which causes the
bridge to change its MAC address, thereby disrupting network communications
for a period of time.

With this update, libvirt now sets an explicit MAC address for all TAP
devices created using the configured MAC address from the XML, but with the
high bit set to 0xFE. The result is that TAP device MAC addresses are now
numerically greater than those for physical interfaces, and bridges should
no longer attempt to switch their MAC address to that of the TAP device,
thus avoiding potential spurious network disruptions. (BZ#617243)

* a memory leak in the libvirt driver for the Xen hypervisor has been fixed
with this update. (BZ#619711)

* the xm and virsh management user interfaces for virtual guests can be
called on the command line to list the number of active guests. However,
under certain circumstances, running the "virsh list" command resulted in
virsh not listing all of the virtual guests that were active (that is,
running) at the time. This update incorporates a fix that matches the logic
used for determining active guests with that of "xm list", such that both
commands should now list the same number of active virtual guests under all
circumstances. (BZ#618200)

All users of libvirt are advised to upgrade to these updated packages,
which contain backported patches to correct these issues. After installing
the updated packages, the system must be rebooted for the update to 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
http://kbase.redhat.com/faq/docs/DOC-11259

Updated packages

RHEL Desktop Multi OS (v. 5 client)

SRPMS:
libvirt-0.6.3-33.el5_5.3.src.rpm
File outdated by:  RHBA-2013:0575
    MD5: 9aafd0faa88ec6aaf969d7043472ef48
SHA-256: 419387cae732f9102c5d9587626c82435873d390dce4511a4335a4c449c7af91
 
IA-32:
libvirt-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 08adec44136ecb4660c35a4d0f49391f
SHA-256: afa56c84cc78d99893acd24dcf251fcd5ac5517f0df49ef1ace00774b00cd3a5
libvirt-devel-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 65f9d2302b1092f78f34cac8023a229a
SHA-256: a2eb76a9c31fc4893211cddfb3a946aaf24127f80dee0f6cf9cd185c10956df1
libvirt-python-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 34fcc631c8dcd0c63e50a80cda34e606
SHA-256: 3a5460f53cd2d383aefe5cd7e4210c88e9915ba02a3d03efb5785272274ce033
 
x86_64:
libvirt-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 08adec44136ecb4660c35a4d0f49391f
SHA-256: afa56c84cc78d99893acd24dcf251fcd5ac5517f0df49ef1ace00774b00cd3a5
libvirt-0.6.3-33.el5_5.3.x86_64.rpm
File outdated by:  RHBA-2013:0575
    MD5: 65d5c4947f657920e0830d02c7205d6e
SHA-256: 425d17bf7de9f89fc337e752170ce1178441bf7e916af6ab144e40fa8b5465c6
libvirt-devel-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 65f9d2302b1092f78f34cac8023a229a
SHA-256: a2eb76a9c31fc4893211cddfb3a946aaf24127f80dee0f6cf9cd185c10956df1
libvirt-devel-0.6.3-33.el5_5.3.x86_64.rpm
File outdated by:  RHBA-2013:0575
    MD5: e90a840aae2e7c459d897289cee0bfe0
SHA-256: 7326612306f54a62a5e0a5a4870bef7e68d36a6fbec4e607b447fad257f6fe2d
libvirt-python-0.6.3-33.el5_5.3.x86_64.rpm
File outdated by:  RHBA-2013:0575
    MD5: bc9dc44a3e8bb46ea96d2f58062c8e66
SHA-256: 7d5355f296f19adf75ca638f7ae28f3e945fdd3be97681ec887a60de9426ce3e
 
RHEL Virtualization (v. 5 server)

SRPMS:
libvirt-0.6.3-33.el5_5.3.src.rpm
File outdated by:  RHBA-2013:0575
    MD5: 9aafd0faa88ec6aaf969d7043472ef48
SHA-256: 419387cae732f9102c5d9587626c82435873d390dce4511a4335a4c449c7af91
 
IA-32:
libvirt-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 08adec44136ecb4660c35a4d0f49391f
SHA-256: afa56c84cc78d99893acd24dcf251fcd5ac5517f0df49ef1ace00774b00cd3a5
libvirt-devel-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 65f9d2302b1092f78f34cac8023a229a
SHA-256: a2eb76a9c31fc4893211cddfb3a946aaf24127f80dee0f6cf9cd185c10956df1
libvirt-python-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 34fcc631c8dcd0c63e50a80cda34e606
SHA-256: 3a5460f53cd2d383aefe5cd7e4210c88e9915ba02a3d03efb5785272274ce033
 
IA-64:
libvirt-0.6.3-33.el5_5.3.ia64.rpm
File outdated by:  RHBA-2013:0575
    MD5: 31386955ce29600a1c7b90d3085c9e8d
SHA-256: d2faa18e81e67fa2a98c11f7428aeed6460b6c6f730ce6d47f345becd7f9de73
libvirt-devel-0.6.3-33.el5_5.3.ia64.rpm
File outdated by:  RHBA-2013:0575
    MD5: c885bc5108059e72e4ebc214acfec5ca
SHA-256: 873e238942af2437e35802ad2b1a1bf5559c50298935148a9e5901e1a7254b61
libvirt-python-0.6.3-33.el5_5.3.ia64.rpm
File outdated by:  RHBA-2013:0575
    MD5: 0c353ebcd0fa7eea147431422ee8fea0
SHA-256: 580a2a123e3ec4e7b56968b00c556b0f7f55f0df65ec6628e84699362ecc8532
 
x86_64:
libvirt-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 08adec44136ecb4660c35a4d0f49391f
SHA-256: afa56c84cc78d99893acd24dcf251fcd5ac5517f0df49ef1ace00774b00cd3a5
libvirt-0.6.3-33.el5_5.3.x86_64.rpm
File outdated by:  RHBA-2013:0575
    MD5: 65d5c4947f657920e0830d02c7205d6e
SHA-256: 425d17bf7de9f89fc337e752170ce1178441bf7e916af6ab144e40fa8b5465c6
libvirt-devel-0.6.3-33.el5_5.3.i386.rpm
File outdated by:  RHBA-2013:0575
    MD5: 65f9d2302b1092f78f34cac8023a229a
SHA-256: a2eb76a9c31fc4893211cddfb3a946aaf24127f80dee0f6cf9cd185c10956df1
libvirt-devel-0.6.3-33.el5_5.3.x86_64.rpm
File outdated by:  RHBA-2013:0575
    MD5: e90a840aae2e7c459d897289cee0bfe0
SHA-256: 7326612306f54a62a5e0a5a4870bef7e68d36a6fbec4e607b447fad257f6fe2d
libvirt-python-0.6.3-33.el5_5.3.x86_64.rpm
File outdated by:  RHBA-2013:0575
    MD5: bc9dc44a3e8bb46ea96d2f58062c8e66
SHA-256: 7d5355f296f19adf75ca638f7ae28f3e945fdd3be97681ec887a60de9426ce3e
 
(The unlinked packages above are only available from the Red Hat Network)

Bugs fixed (see bugzilla for more information)

602455 - CVE-2010-2242 libvirt: improperly mapped source privileged ports may allow for obtaining privileged resources on the host
607812 - CVE-2010-2239 libvirt: not setting user defined backing store format when creating new image
617243 - libvirt should not use the MAC address assigned to tap devices/vnet interfaces by the TAP/TUN driver.
618200 - Discrepancy between xm and virsh output when listing active Xen domains
619711 - Memory leak in libvirtd


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/