7.8 - USN-3575-1

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

- Ubuntu 17.10 - Ubuntu 16.04 LTS - Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in QEMU.

Software Description: - qemu: Machine emulator and virtualizer

Details:

It was discovered that QEMU incorrectly handled guest ram. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2017-11334)

David Buchanan discovered that QEMU incorrectly handled the VGA device. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. This issue was only addressed in Ubuntu 17.10. (CVE-2017-13672)

Thomas Garnier discovered that QEMU incorrectly handled multiboot. An attacker 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 affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2017-14167)

Tuomas Tynkkynen discovered that QEMU incorrectly handled VirtFS directory sharing. An attacker could use this issue to obtain sensitive information from host memory. (CVE-2017-15038)

Eric Blake discovered that QEMU incorrectly handled memory in the NBD server. An attacker could use this issue to cause the NBD server to crash, resulting in a denial of service. This issue only affected Ubuntu 17.10. (CVE-2017-15118)

Eric Blake discovered that QEMU incorrectly handled certain options to the NBD server. An attacker could use this issue to cause the NBD server to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2017-15119)

Daniel Berrange discovered that QEMU incorrectly handled the VNC server. A remote attacker could possibly use this issue to consume memory, resulting in a denial of service. This issue was only addressed in Ubuntu 17.10. (CVE-2017-15124)

Carl Brassey discovered that QEMU incorrectly handled certain websockets. A remote attacker could possibly use this issue to consume memory, resulting in a denial of service. This issue only affected Ubuntu 17.10. (CVE-2017-15268)

Guoxiang Niu discovered that QEMU incorrectly handled the Cirrus VGA device. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2017-15289)

Cyrille Chatras discovered that QEMU incorrectly handled certain PS2 values during migration. An attacker could possibly use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 17.10. (CVE-2017-16845)

It was discovered that QEMU incorrectly handled the Virtio Vring implementation. An attacker could possibly use this issue to cause QEMU to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 17.10. (CVE-2017-17381)

Eric Blake discovered that QEMU incorrectly handled certain rounding operations. An attacker could possibly use this issue to cause QEMU to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2017-18043)

Jiang Xin and Lin ZheCheng discovered that QEMU incorrectly handled the VGA device. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2018-5683)

Update instructions:

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

Ubuntu 17.10:
qemu-system 1:2.10+dfsg-0ubuntu3.5
qemu-system-aarch64 1:2.10+dfsg-0ubuntu3.5
qemu-system-arm 1:2.10+dfsg-0ubuntu3.5
qemu-system-mips 1:2.10+dfsg-0ubuntu3.5
qemu-system-misc 1:2.10+dfsg-0ubuntu3.5
qemu-system-ppc 1:2.10+dfsg-0ubuntu3.5
qemu-system-s390x 1:2.10+dfsg-0ubuntu3.5
qemu-system-sparc 1:2.10+dfsg-0ubuntu3.5
qemu-system-x86 1:2.10+dfsg-0ubuntu3.5

Ubuntu 16.04 LTS:
qemu-system 1:2.5+dfsg-5ubuntu10.22
qemu-system-aarch64 1:2.5+dfsg-5ubuntu10.22
qemu-system-arm 1:2.5+dfsg-5ubuntu10.22
qemu-system-mips 1:2.5+dfsg-5ubuntu10.22
qemu-system-misc 1:2.5+dfsg-5ubuntu10.22
qemu-system-ppc 1:2.5+dfsg-5ubuntu10.22
qemu-system-s390x 1:2.5+dfsg-5ubuntu10.22
qemu-system-sparc 1:2.5+dfsg-5ubuntu10.22
qemu-system-x86 1:2.5+dfsg-5ubuntu10.22

Ubuntu 14.04 LTS:
qemu-system 2.0.0+dfsg-2ubuntu1.39
qemu-system-aarch64 2.0.0+dfsg-2ubuntu1.39
qemu-system-arm 2.0.0+dfsg-2ubuntu1.39
qemu-system-mips 2.0.0+dfsg-2ubuntu1.39
qemu-system-misc 2.0.0+dfsg-2ubuntu1.39
qemu-system-ppc 2.0.0+dfsg-2ubuntu1.39
qemu-system-sparc 2.0.0+dfsg-2ubuntu1.39
qemu-system-x86 2.0.0+dfsg-2ubuntu1.39

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

References:
https://www.ubuntu.com/usn/usn-3575-1
CVE-2017-11334, CVE-2017-13672, CVE-2017-14167, CVE-2017-15038,
CVE-2017-15118, CVE-2017-15119, CVE-2017-15124, CVE-2017-15268,
CVE-2017-15289, CVE-2017-16845, CVE-2017-17381, CVE-2017-18043,
CVE-2018-5683

Package Information:
https://launchpad.net/ubuntu/+source/qemu/1:2.10+dfsg-0ubuntu3.5
https://launchpad.net/ubuntu/+source/qemu/1:2.5+dfsg-5ubuntu10.22
https://launchpad.net/ubuntu/+source/qemu/2.0.0+dfsg-2ubuntu1.39