Ciborg gem for Ruby allows local users to write files and gain privileges via Symlink

There is a /tmp file race condition in chef/travis-cookbooks/ci_environment/perlbrew/recipes/default.rb in the ciborg gem 3.0.0 when creating /tmp/perlbrew-installer. If a malicious local user creates the file first they can overwrite the contents with their own code executing it as the ciborg process owner.