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Alerts This Week
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RHEL 5: RHSA-2016-1943-01 Critical Update for KVM Denial of Service Risk

red hat
Calendar Grey September 27, 2016
Scroller Redhat
The recent Red Hat Security Bulletin highlights a significant kvm patch aimed at remedying severe vulnerabilities affecting RHEL 6 customers.
An update for kvm is now available for Red Hat Enterprise Linux 5

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

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

Note: The procedure in the Solution section must be performed before this update will take effect.

Summary

KVM (for Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware. Using KVM, one can run multiple virtual machines running unmodified Linux or Windows images. Each virtual machine has private virtualized hardware: a network card, disk, graphics adapter, etc.
Security Fix(es):
* An out-of-bounds read/write access flaw was found in the way QEMU's VGA emulation with VESA BIOS Extensions (VBE) support performed read/write operations using I/O port methods. A privileged guest user could use this flaw to execute arbitrary code on the host with the privileges of the host's QEMU process. (CVE-2016-3710)
* Quick Emulator(QEMU) built with the virtio framework is vulnerable to an unbounded memory allocation issue. It was found that a malicious guest user could submit more requests than the virtqueue size permits. Processing a request allocates a VirtQueueElement results in unbounded memory allocation on the host controlled by the guest. (CVE-2016-5403)
Red Hat would like to thank Wei Xiao (360 Marvel Team) and Qinghao Tang (360 Marvel Team) for reporting CVE-2016-3710 and hongzhenhao (Marvel Team) for reporting CVE-2016-5403.

Topics%20covered

Topics Covered

security advisory security issue red hat important doS kvm kernel-based virtual machine

References

https://access.redhat.com/security/cve/CVE-2016-3710 https://access.redhat.com/security/cve/CVE-2016-5403 https://access.redhat.com/security/updates/classification/#important

Package List

Red Hat Enterprise Linux Desktop Multi OS (v. 5 client):
Source: kvm-83-276.el5_11.src.rpm
x86_64: kmod-kvm-83-276.el5_11.x86_64.rpm kmod-kvm-debug-83-276.el5_11.x86_64.rpm kvm-83-276.el5_11.x86_64.rpm kvm-debuginfo-83-276.el5_11.x86_64.rpm kvm-qemu-img-83-276.el5_11.x86_64.rpm kvm-tools-83-276.el5_11.x86_64.rpm
Red Hat Enterprise Linux Virtualization (v. 5 server):
Source: kvm-83-276.el5_11.src.rpm
x86_64: kmod-kvm-83-276.el5_11.x86_64.rpm kmod-kvm-debug-83-276.el5_11.x86_64.rpm kvm-83-276.el5_11.x86_64.rpm kvm-debuginfo-83-276.el5_11.x86_64.rpm kvm-qemu-img-83-276.el5_11.x86_64.rpm kvm-tools-83-276.el5_11.x86_64.rpm
These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from https://access.redhat.com/security/team/key/


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2016:1943-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2016:1943.html
Issue date: 2016-09-27

Topic

An update for kvm is now available for Red Hat Enterprise Linux 5.Red Hat Product Security has rated this update as having a security impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.

Topics%20covered

Topics Covered

security advisory security issue red hat important doS kvm kernel-based virtual machine

Relevant Releases Architectures

Red Hat Enterprise Linux Desktop Multi OS (v. 5 client) - x86_64

Red Hat Enterprise Linux Virtualization (v. 5 server) - x86_64

Bugs Fixed

1331401 - CVE-2016-3710 qemu: incorrect banked access bounds checking in vga module

1358359 - CVE-2016-5403 Qemu: virtio: unbounded memory allocation on host via guest leading to DoS

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