Dancer::Plugin::Auth::Google versions through 0.07 for Perl have TLS verification disabled. The default user agent is initialised with SSL_verify_mode explicitly disabled. An attacker with network man-in-the-middle (MITM) capability between the Dancer application and googleapis.com can intercept the OAuth2 token exchange and userinfo fetch, return a forged access_token and user profile, and be logged in to the Dancer application as any Google user.
Analyzing vulnerability vectors…