=========================================================================Ubuntu Security Notice USN-3934-1
April 03, 2019

policykit-1 vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

PolicyKit could allow unintended access.

Software Description:
- policykit-1: framework for managing administrative policies and privileges

Details:

It was discovered that PolicyKit incorrectly relied on the fork() system
call in the Linux kernel being atomic. A local attacker could possibly use
this issue to gain access to services that have cached authorizations.

Update instructions:

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

Ubuntu 18.10:
  libpolkit-backend-1-0           0.105-21ubuntu0.4
  policykit-1                     0.105-21ubuntu0.4

Ubuntu 18.04 LTS:
  libpolkit-backend-1-0           0.105-20ubuntu0.18.04.5
  policykit-1                     0.105-20ubuntu0.18.04.5

Ubuntu 16.04 LTS:
  libpolkit-backend-1-0           0.105-14.1ubuntu0.5
  policykit-1                     0.105-14.1ubuntu0.5

Ubuntu 14.04 LTS:
  libpolkit-backend-1-0           0.105-4ubuntu3.14.04.6
  policykit-1                     0.105-4ubuntu3.14.04.6

After a standard system update you need to reboot your computer to make
all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-3934-1
  CVE-2019-6133

Package Information:
  https://launchpad.net/ubuntu/+source/policykit-1/0.105-21ubuntu0.4
  https://launchpad.net/ubuntu/+source/policykit-1/0.105-20ubuntu0.18.04.5
  https://launchpad.net/ubuntu/+source/policykit-1/0.105-14.1ubuntu0.5
  https://launchpad.net/ubuntu/+source/policykit-1/0.105-4ubuntu3.14.04.6