A libproxy security update has been released for Ubuntu 16.04 LTS, 18.04 LTS, 20.04 LTS, and 20.10.

USN-4673-1: libproxy vulnerability

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Ubuntu Security Notice USN-4673-1
January 04, 2021

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

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

libproxy could be made to crash or execute arbitrary code if it received a specially
crafted file.

Software Description:
- libproxy: automatic proxy configuration management library

Details:

Li Fei discovered that libproxy incorrectly handled certain PAC files.
An attacker could possibly use this issue to cause a crash or execute arbitrary
code.

Update instructions:

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

Ubuntu 20.10:
libproxy1v5 0.4.15-13ubuntu1.1

Ubuntu 20.04 LTS:
libproxy1v5 0.4.15-10ubuntu1.2

Ubuntu 18.04 LTS:
libproxy1v5 0.4.15-1ubuntu0.2

Ubuntu 16.04 LTS:
libproxy1v5 0.4.11-5ubuntu1.2

In general, a standard system update will make all the necessary changes.

References:
  https://usn.ubuntu.com/4673-1
CVE-2020-26154

Package Information:
  https://launchpad.net/ubuntu/+source/libproxy/0.4.15-13ubuntu1.1
  https://launchpad.net/ubuntu/+source/libproxy/0.4.15-10ubuntu1.2
  https://launchpad.net/ubuntu/+source/libproxy/0.4.15-1ubuntu0.2
  https://launchpad.net/ubuntu/+source/libproxy/0.4.11-5ubuntu1.2