USN-3047-2: QEMU regression

12 August 2016

qemu, qemu-kvm regression

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS

Summary

USN-3047-1 introduced a regression in QEMU.

Software Description

  • qemu - Machine emulator and virtualizer
  • qemu-kvm - Machine emulator and virtualizer

Details

USN-3047-1 fixed vulnerabilities in QEMU. The patch to fix CVE-2016-5403 caused a regression which resulted in save/restore failures when virtio memory balloon statistics are enabled. This update temporarily reverts the security fix for CVE-2016-5403 pending further investigation. We apologize for the inconvenience.

Original advisory details:

Li Qiang discovered that QEMU incorrectly handled 53C9X Fast SCSI controller emulation. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code on the host. In the default installation, when QEMU is used with libvirt, attackers would be isolated by the libvirt AppArmor profile. This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-4439, CVE-2016-4441, CVE-2016-5238, CVE-2016-5338, CVE-2016-6351)

Li Qiang and Qinghao Tang discovered that QEMU incorrectly handled the VMWare VGA module. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly to obtain sensitive host memory. (CVE-2016-4453, CVE-2016-4454)

Li Qiang discovered that QEMU incorrectly handled VMWARE PVSCSI paravirtual SCSI bus emulation support. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-4952)

Li Qiang discovered that QEMU incorrectly handled MegaRAID SAS 8708EM2 Host Bus Adapter emulation support. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly to obtain sensitive host memory. This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-5105, CVE-2016-5106, CVE-2016-5107, CVE-2016-5337)

It was discovered that QEMU incorrectly handled certain iSCSI asynchronous I/O ioctl calls. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code on the host. In the default installation, when QEMU is used with libvirt, attackers would be isolated by the libvirt AppArmor profile. This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-5126)

Zhenhao Hong discovered that QEMU incorrectly handled the Virtio module. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2016-5403)

Update instructions

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

Ubuntu 16.04 LTS
qemu-system - 1:2.5+dfsg-5ubuntu10.4
qemu-system-aarch64 - 1:2.5+dfsg-5ubuntu10.4
qemu-system-arm - 1:2.5+dfsg-5ubuntu10.4
qemu-system-mips - 1:2.5+dfsg-5ubuntu10.4
qemu-system-misc - 1:2.5+dfsg-5ubuntu10.4
qemu-system-ppc - 1:2.5+dfsg-5ubuntu10.4
qemu-system-s390x - 1:2.5+dfsg-5ubuntu10.4
qemu-system-sparc - 1:2.5+dfsg-5ubuntu10.4
qemu-system-x86 - 1:2.5+dfsg-5ubuntu10.4
Ubuntu 14.04 LTS
qemu-system - 2.0.0+dfsg-2ubuntu1.27
qemu-system-aarch64 - 2.0.0+dfsg-2ubuntu1.27
qemu-system-arm - 2.0.0+dfsg-2ubuntu1.27
qemu-system-mips - 2.0.0+dfsg-2ubuntu1.27
qemu-system-misc - 2.0.0+dfsg-2ubuntu1.27
qemu-system-ppc - 2.0.0+dfsg-2ubuntu1.27
qemu-system-sparc - 2.0.0+dfsg-2ubuntu1.27
qemu-system-x86 - 2.0.0+dfsg-2ubuntu1.27
Ubuntu 12.04 LTS
qemu-kvm - 1.0+noroms-0ubuntu14.30

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References