Preface: In general, Ruby is a good language for game development. Apart from that Ruby has been used by companies like Twitter, Airbnb, Shopify, Github, Slideshare, Basecamp and Shopify.
Synopsis: RubyGems is a package manager for the Ruby programming language that provides a standard format for distributing Ruby programs and libraries (in a self-contained format called a “gem”).
Vulnerability details: CVE-2019-8324: Installing a malicious gem may lead to arbitrary code execution. For more details, please refer to attached diagram.
Remedy: RubyGems has released software updates at the following link: https://rubygems.org/pages/download