[USN-4355-1] PulseAudio vulnerability

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Ubuntu Security Notice USN-4355-1
May 12, 2020

pulseaudio vulnerability
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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:

PulseAudio could allow unintended access to snap packages.

Software Description:
- pulseaudio: PulseAudio sound server

Details:

PulseAudio in Ubuntu contains additional functionality to mediate audio
recording for snap packages and it was discovered that this functionality
did not mediate PulseAudio module unloading. An attacker-controlled snap
with only the audio-playback interface connected could exploit this to
bypass access controls and record audio.

Update instructions:

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

Ubuntu 20.04 LTS:
pulseaudio 1:13.99.1-1ubuntu3.2

Ubuntu 19.10:
pulseaudio 1:13.0-1ubuntu1.2

Ubuntu 18.04 LTS:
pulseaudio 1:11.1-1ubuntu7.7

Ubuntu 16.04 LTS:
pulseaudio 1:8.0-0ubuntu3.12

After a standard system update you need to restart your session to make
all the necessary changes.

References:
https://usn.ubuntu.com/4355-1
CVE-2020-11931, https://launchpad.net/bugs/1877102

Package Information:
https://launchpad.net/ubuntu/+source/pulseaudio/1:13.99.1-1ubuntu3.2
https://launchpad.net/ubuntu/+source/pulseaudio/1:13.0-1ubuntu1.2
https://launchpad.net/ubuntu/+source/pulseaudio/1:11.1-1ubuntu7.7
https://launchpad.net/ubuntu/+source/pulseaudio/1:8.0-0ubuntu3.12