A fastd security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, and 20.10.

USN-4718-1: fastd vulnerability

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Ubuntu Security Notice USN-4718-1
February 02, 2021

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

- Ubuntu 20.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

fastd could be made to denial of service it if received a specially crafted input.

Software Description:
- fastd: Fast and Secure Tunneling Daemon

Details:

It was discovered that fastd incorrectly handled certain packets.
An attacker could possibly use this issue to cause a denial of service.

Update instructions:

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

Ubuntu 20.10:
fastd 19-3ubuntu0.1

Ubuntu 18.04 LTS:
fastd 18-3ubuntu0.18.04.1

Ubuntu 16.04 LTS:
fastd 17-4ubuntu0.1

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

References:
  https://usn.ubuntu.com/4718-1
CVE-2020-27638

Package Information:
  https://launchpad.net/ubuntu/+source/fastd/19-3ubuntu0.1
  https://launchpad.net/ubuntu/+source/fastd/18-3ubuntu0.18.04.1
  https://launchpad.net/ubuntu/+source/fastd/17-4ubuntu0.1