Design/Logic Flaw

A vulnerability in the London Trust Media Private Internet Access (PIA) VPN Client v82 for Linux could allow an authenticated, local attacker to run arbitrary code with elevated privileges. The root_runner.64 binary is setuid root. This binary executes /opt/pia/ruby/64/ruby, which in turn attempts to load several libraries under /tmp/ruby-deploy.old/lib. A local unprivileged user can create a malicious library under this path to execute arbitrary code as the root user.