RHSA-2013:0746 - Security Advisory

Topic

An updated rhev-hypervisor6 package that fixes several security issues and
various bugs is now available.

The Red Hat Security Response Team has rated this update as having
important 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.

Description

The rhev-hypervisor6 package provides a Red Hat Enterprise Virtualization
Hypervisor ISO disk image. The Red Hat Enterprise Virtualization Hypervisor
is a dedicated Kernel-based Virtual Machine (KVM) hypervisor. It includes
everything necessary to run and manage virtual machines: A subset of the
Red Hat Enterprise Linux operating environment and the Red Hat Enterprise
Virtualization Agent.

Note: Red Hat Enterprise Virtualization Hypervisor is only available for
the Intel 64 and AMD64 architectures with virtualization extensions.

A flaw was found in the way KVM handled guest time updates when the buffer
the guest registered by writing to the MSR_KVM_SYSTEM_TIME machine state
register (MSR) crossed a page boundary. A privileged guest user could use
this flaw to crash the host or, potentially, escalate their privileges,
allowing them to execute arbitrary code at the host kernel level.
(CVE-2013-1796)

A potential use-after-free flaw was found in the way KVM handled guest time
updates when the GPA (guest physical address) the guest registered by
writing to the MSR_KVM_SYSTEM_TIME machine state register (MSR) fell into a
movable or removable memory region of the hosting user-space process (by
default, QEMU-KVM) on the host. If that memory region is deregistered from
KVM using KVM_SET_USER_MEMORY_REGION and the allocated virtual memory
reused, a privileged guest user could potentially use this flaw to escalate
their privileges on the host. (CVE-2013-1797)

A flaw was found in the way KVM emulated IOAPIC (I/O Advanced Programmable
Interrupt Controller). A missing validation check in the
ioapic_read_indirect() function could allow a privileged guest user to
crash the host, or read a substantial portion of host kernel memory.
(CVE-2013-1798)

An integer overflow flaw was discovered in one of pixman's manipulation
routines. If a remote attacker could trick an application using pixman into
performing a certain manipulation, it could cause the application to crash
or, possibly, execute arbitrary code with the privileges of the user
running the application. (CVE-2013-1591)

Red Hat would like to thank Andrew Honig of Google for reporting
CVE-2013-1796, CVE-2013-1797, and CVE-2013-1798.

This updated package provides updated components that include fixes for
various security issues. These issues have no security impact on Red Hat
Enterprise Virtualization Hypervisor itself, however. The security fixes
included in this update address the following CVE numbers:

CVE-2013-2266 (a bind issue)

CVE-2012-5195, CVE-2012-5526, CVE-2012-6329, and CVE-2013-1667 (perl
issues)

This update contains the fixes from the following errata:

ovirt-node: RHBA-2013:0745
libvirt: RHBA-2013:0725
vdsm: RHBA-2013:0704
kernel: RHSA-2013:0744

Users of the Red Hat Enterprise Virtualization Hypervisor are advised to
upgrade to this updated package, which corrects these issues.

Solution

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

To upgrade Hypervisors in Red Hat Enterprise Virtualization
environments using the disk image provided by this package, refer to:

https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Hypervisor_Deployment_Guide/chap-Deployment_Guide-Upgrading_Red_Hat_Enterprise_Virtualization_Hypervisors.html

Affected Products

• Red Hat Virtualization 6 x86_64

Fixes

• BZ - 910149 - CVE-2013-1591 pixman: stack-based buffer overflow
• BZ - 917012 - CVE-2013-1796 kernel: kvm: buffer overflow in handling of MSR_KVM_SYSTEM_TIME
• BZ - 917013 - CVE-2013-1797 kernel: kvm: after free issue with the handling of MSR_KVM_SYSTEM_TIME
• BZ - 917017 - CVE-2013-1798 kernel: kvm: out-of-bounds access in ioapic indirect register reads
• BZ - 950154 - rhev-hypervisor 6.4 Update 2 release

CVEs

• CVE-2013-1591
• CVE-2013-1798
• CVE-2013-1796
• CVE-2013-1797

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Hypervisor_Deployment_Guide/chap-Deployment_Guide-Upgrading_Red_Hat_Enterprise_Virtualization_Hypervisors.html
• https://rhn.redhat.com/errata/RHBA-2013-0745.html
• https://rhn.redhat.com/errata/RHBA-2013-0725.html
• https://rhn.redhat.com/errata/RHBA-2013-0704.html
• https://rhn.redhat.com/errata/RHSA-2013-0744.html