Overly broad permissions can turn one compromised account into a much larger security problem. Learn how to reduce unnecessary access, review privileges, and apply least privilege across modern Linux systems. Review Linux Privileges×

Alerts This Week
Warning Icon 1 542
Alerts This Week
Warning Icon 1 542

Red Hat Enterprise Linux 7 RHSA-2017:0396-01 Important qemu-kvm DoS

red hat
Calendar Grey March 2, 2017
Scroller Redhat
Red Hat has issued a crucial advisory regarding a significant update for qemu-kvm, aimed at resolving pressing security vulnerabilities and rectifying bugs for Enterprise Linux.
An update for qemu-kvm is now available for Red Hat Enterprise Linux 7

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

After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.

Summary

Kernel-based Virtual Machine (KVM) is a full virtualization solution for Linux on a variety of architectures. The qemu-kvm packages provide the user-space component for running virtual machines that use KVM.
Security Fix(es):
* Quick emulator (QEMU) built with the Cirrus CLGD 54xx VGA emulator support is vulnerable to an out-of-bounds access issue. It could occur while copying VGA data via bitblt copy in backward mode. A privileged user inside a guest could use this flaw to crash the QEMU process resulting in DoS or potentially execute arbitrary code on the host with privileges of QEMU process on the host. (CVE-2017-2615)
* Quick emulator (QEMU) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to an out-of-bounds access issue. The issue could occur while copying VGA data in cirrus_bitblt_cputovideo. A privileged user inside guest could use this flaw to crash the QEMU process OR potentially execute arbitrary code on host with privileges of the QEMU process. (CVE-2017-2620)
Red Hat would like to thank Wjjzhang (Tencent.com Inc.) and Li Qiang (360.cn Inc.) for reporting CVE-2017-2615.
Bug Fix(es):
* When using the virtio-blk driver on a guest virtual machine with no space on the virtual hard drive, the guest terminated unexpectedly with a "block I/O error in device" message and the qemu-kvm process exited with a segmentation fault. This update fixes how the system_reset QEMU signal is handled in the above scenario. As a result, if a guest crashes due to no space left on the device, qemu-kvm continues running and the guest can be reset as expected. (BZ#1420049)

Topics%20covered

Topics Covered

security advisory bug fix DoS Red Hat Enterprise Linux important qemu-kvm

References

https://access.redhat.com/security/cve/CVE-2017-2615 https://access.redhat.com/security/cve/CVE-2017-2620 https://access.redhat.com/security/updates/classification/#important

Package List

Red Hat Enterprise Linux Client (v. 7):
Source: qemu-kvm-1.5.3-126.el7_3.5.src.rpm
x86_64: qemu-img-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-common-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-debuginfo-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-tools-1.5.3-126.el7_3.5.x86_64.rpm
Red Hat Enterprise Linux ComputeNode Optional (v. 7):
Source: qemu-kvm-1.5.3-126.el7_3.5.src.rpm
x86_64: qemu-img-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-common-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-debuginfo-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-tools-1.5.3-126.el7_3.5.x86_64.rpm
Red Hat Enterprise Linux Server (v. 7):
Source: qemu-kvm-1.5.3-126.el7_3.5.src.rpm
ppc64: qemu-img-1.5.3-126.el7_3.5.ppc64.rpm qemu-kvm-debuginfo-1.5.3-126.el7_3.5.ppc64.rpm
ppc64le: qemu-img-1.5.3-126.el7_3.5.ppc64le.rpm qemu-kvm-debuginfo-1.5.3-126.el7_3.5.ppc64le.rpm
x86_64: qemu-img-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-common-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-debuginfo-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-tools-1.5.3-126.el7_3.5.x86_64.rpm
Red Hat Enterprise Linux Workstation (v. 7):
Source: qemu-kvm-1.5.3-126.el7_3.5.src.rpm
x86_64: qemu-img-1.5.3-126.el7_3.5.x86_64.rpm qemu-kvm-1.5.3-126.el7_3.5.x86_64.rpm

Read the Full Advisory


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2017:0396-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2017:0396.html
Issue date: 2017-03-02

Topic

An update for qemu-kvm is now available for Red Hat Enterprise Linux 7.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 bug fix DoS Red Hat Enterprise Linux important qemu-kvm

Relevant Releases Architectures

Red Hat Enterprise Linux Client (v. 7) - x86_64

Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64

Red Hat Enterprise Linux Server (v. 7) - ppc64, ppc64le, x86_64

Red Hat Enterprise Linux Workstation (v. 7) - x86_64

Bugs Fixed

1418200 - CVE-2017-2615 Qemu: display: cirrus: oob access while doing bitblt copy backward mode

1420049 - system_reset should clear pending request for error (virtio-blk)

1420428 - Remove dependencies required by spice on ppc64le

1420484 - CVE-2017-2620 Qemu: display: cirrus: potential arbitrary code execution via cirrus_bitblt_cputovideo

Get the latest News and Insights

Get the latest Linux and open source security news straight to your inbox.