A Gon gem security update has been released for Ubuntu Linux 18.04 LTS.

USN-4560-1: Gon gem vulnerability

==========================================================================
Ubuntu Security Notice USN-4560-1
September 30, 2020

ruby-gon vulnerability
==========================================================================

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

- Ubuntu 18.04 LTS

Summary:

Gon gem could be made to run programs if it received specially crafted network
traffic.

Software Description:
- ruby-gon: Ruby library to send data to JavaScript from a Ruby application

Details:

It was discovered that Gon gem did not properly escape certain input. An
attacker could use this vulnerability to execute a cross-site scripting
(XSS) attack.

Update instructions:

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

Ubuntu 18.04 LTS:
ruby-gon 6.1.0-1+deb9u1build0.18.04.1

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

References:
  https://usn.ubuntu.com/4560-1
CVE-2020-25739

Package Information:
  https://launchpad.net/ubuntu/+source/ruby-gon/6.1.0-1+deb9u1build0.18.04.1