==========================================================================
Ubuntu Security Notice USN-4372-1
May 21, 2020

qemu vulnerabilities
==========================================================================

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

- Ubuntu 20.04 LTS
- Ubuntu 19.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in QEMU.

Software Description:
- qemu: Machine emulator and virtualizer

Details:

It was discovered that QEMU incorrectly handled bochs-display devices. A
local attacker in a guest could use this to cause a denial of service or
possibly execute arbitrary code in the host. This issue only affected
Ubuntu 19.10. (CVE-2019-15034)

It was discovered that QEMU incorrectly handled memory during certain VNC
operations. A remote attacker could possibly use this issue to cause QEMU
to consume resources, resulting in a denial of service. This issue only
affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 19.10.
(CVE-2019-20382)

It was discovered that QEMU incorrectly generated QEMU Pointer
Authentication signatures on ARM. A local attacker could possibly use this
issue to bypass PAuth. This issue only affected Ubuntu 19.10.
(CVE-2020-10702)

Ziming Zhang discovered that QEMU incorrectly handled ATI VGA emulation. A
local attacker in a guest could use this issue to cause QEMU to crash,
resulting in a denial of service. This issue only affected Ubuntu 20.04
LTS. (CVE-2020-11869)

Aviv Sasson discovered that QEMU incorrectly handled Slirp networking. A
remote attacker could 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, Ubuntu 18.04 LTS, and Ubuntu 19.10.
(CVE-2020-1983)

Update instructions:

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

Ubuntu 20.04 LTS:
  qemu                            1:4.2-3ubuntu6.1
  qemu-system                     1:4.2-3ubuntu6.1
  qemu-system-arm                 1:4.2-3ubuntu6.1
  qemu-system-mips                1:4.2-3ubuntu6.1
  qemu-system-ppc                 1:4.2-3ubuntu6.1
  qemu-system-s390x               1:4.2-3ubuntu6.1
  qemu-system-sparc               1:4.2-3ubuntu6.1
  qemu-system-x86                 1:4.2-3ubuntu6.1

Ubuntu 19.10:
  qemu                            1:4.0+dfsg-0ubuntu9.6
  qemu-system                     1:4.0+dfsg-0ubuntu9.6
  qemu-system-arm                 1:4.0+dfsg-0ubuntu9.6
  qemu-system-mips                1:4.0+dfsg-0ubuntu9.6
  qemu-system-ppc                 1:4.0+dfsg-0ubuntu9.6
  qemu-system-s390x               1:4.0+dfsg-0ubuntu9.6
  qemu-system-sparc               1:4.0+dfsg-0ubuntu9.6
  qemu-system-x86                 1:4.0+dfsg-0ubuntu9.6

Ubuntu 18.04 LTS:
  qemu                            1:2.11+dfsg-1ubuntu7.26
  qemu-system                     1:2.11+dfsg-1ubuntu7.26
  qemu-system-arm                 1:2.11+dfsg-1ubuntu7.26
  qemu-system-mips                1:2.11+dfsg-1ubuntu7.26
  qemu-system-ppc                 1:2.11+dfsg-1ubuntu7.26
  qemu-system-s390x               1:2.11+dfsg-1ubuntu7.26
  qemu-system-sparc               1:2.11+dfsg-1ubuntu7.26
  qemu-system-x86                 1:2.11+dfsg-1ubuntu7.26

Ubuntu 16.04 LTS:
  qemu                            1:2.5+dfsg-5ubuntu10.44
  qemu-system                     1:2.5+dfsg-5ubuntu10.44
  qemu-system-aarch64             1:2.5+dfsg-5ubuntu10.44
  qemu-system-arm                 1:2.5+dfsg-5ubuntu10.44
  qemu-system-mips                1:2.5+dfsg-5ubuntu10.44
  qemu-system-ppc                 1:2.5+dfsg-5ubuntu10.44
  qemu-system-s390x               1:2.5+dfsg-5ubuntu10.44
  qemu-system-sparc               1:2.5+dfsg-5ubuntu10.44
  qemu-system-x86                 1:2.5+dfsg-5ubuntu10.44

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

References:
  https://usn.ubuntu.com/4372-1
  CVE-2019-15034, CVE-2019-20382, CVE-2020-10702, CVE-2020-11869,
  CVE-2020-1983

Package Information:
  https://launchpad.net/ubuntu/+source/qemu/1:4.2-3ubuntu6.1
  https://launchpad.net/ubuntu/+source/qemu/1:4.0+dfsg-0ubuntu9.6
  https://launchpad.net/ubuntu/+source/qemu/1:2.11+dfsg-1ubuntu7.26
  https://launchpad.net/ubuntu/+source/qemu/1:2.5+dfsg-5ubuntu10.44