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Ubuntu 11.04 LTS: USN-1165-1 Critical: QEMU Denial of Service Exploit

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Calendar Grey July 6, 2011
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Ubuntu Security Alert USN-1165-1 addresses vulnerabilities in qemu-kvm that impact several versions. Discover effective strategies to reduce potential threats.
A privileged attacker within a QEMU guest could cause QEMU to crash.

Summary

A privileged attacker within a QEMU guest could cause QEMU to crash.

Software Description:

- qemu-kvm: Machine emulator and virtualizer

Details:

Nelson Elhage discoverd that QEMU did not properly validate certain

virtqueue requests from the guest. An attacker could exploit this to cause

a denial of service of the guest or possibly execute code with the

privileges of the user invoking the program. (CVE-2011-2212)

Stefan Hajnoczi discovered that QEMU did not properly perform integer

comparisons when performing virtqueue input validation. An attacker could

exploit this to cause a denial of service of the guest or possibly execute

code with the privileges of the user invoking the program. (CVE-2011-2512)

When using QEMU with libvirt or virtualization management software based on

libvirt such as Eucalyptus and OpenStack, QEMU guests are individually

isolated by an AppArmor profile by default in Ubuntu.

Topics%20covered

Topics Covered

security advisory denial of service critical ubuntu virtualization qemu-kvm

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 11.04:
  qemu-kvm                        0.14.0+noroms-0ubuntu4.3

Ubuntu 10.10:
  qemu-kvm                        0.12.5+noroms-0ubuntu7.8
  qemu-kvm-extras                 0.12.5+noroms-0ubuntu7.8
  qemu-kvm-extras-static          0.12.5+noroms-0ubuntu7.8

Ubuntu 10.04 LTS:
  qemu-kvm                        0.12.3+noroms-0ubuntu9.12
  qemu-kvm-extras                 0.12.3+noroms-0ubuntu9.12
  qemu-kvm-extras-static          0.12.3+noroms-0ubuntu9.12

After a standard system update you need to restart running virtual machines
to make all the necessary changes.

References

https://ubuntu.com/security/notices/USN-1165-1

CVE-2011-2212, CVE-2011-2512

Severity
critical
Lowest
Low
Medium
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Critical

July 06, 2011

Topics%20covered

Topics Covered

security advisory denial of service critical ubuntu virtualization qemu-kvm

Package Information

https://launchpad.net/ubuntu/+source/qemu-kvm/0.14.0+noroms-0ubuntu4.3
https://launchpad.net/ubuntu/+source/qemu-kvm/0.12.5+noroms-0ubuntu7.8
https://launchpad.net/ubuntu/+source/qemu-kvm/0.12.3+noroms-0ubuntu9.12

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