RHSA-2013:0807 - Security Advisory

Topic

An updated hypervkvpd package that fixes one security issue and one bug is
now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

The hypervkvpd package contains hypervkvpd, the guest Microsoft Hyper-V
Key-Value Pair (KVP) daemon. The daemon passes basic information to the
host through VMBus, such as the guest IP address, fully qualified domain
name, operating system name, and operating system release number.

A denial of service flaw was found in the way hypervkvpd processed certain
Netlink messages. A local, unprivileged user in a guest (running on
Microsoft Hyper-V) could send a Netlink message that, when processed, would
cause the guest's hypervkvpd daemon to exit. (CVE-2012-5532)

The CVE-2012-5532 issue was discovered by Florian Weimer of the Red Hat
Product Security Team.

This update also fixes the following bug:

• The hypervkvpd daemon did not close the file descriptors for pool files

when they were updated. This could eventually lead to hypervkvpd crashing
with a "KVP: Failed to open file, pool: 1" error after consuming all
available file descriptors. With this update, the file descriptors are
closed, correcting this issue. (BZ#953502)

Users of hypervkvpd are advised to upgrade to this updated package, which
contains backported patches to correct these issues. After installing the
update, it is recommended to reboot all guest machines.

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
https://access.redhat.com/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 x86_64
• Red Hat Enterprise Linux Server - AUS 5.9 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - AUS 5.9 ia64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 i386

Fixes

• BZ - 877572 - CVE-2012-5532 hypervkvpd: Netlink source address validation allows denial of service
• BZ - 953502 - hypervkvpd dies from time to time with "KVP: Failed to open file, pool: 1"

CVEs

• CVE-2012-5532

References

• https://access.redhat.com/security/updates/classification/#low