The Firebase Support & Chat Management plugin for WordPress is vulnerable to privilege escalation in all versions up to, and including, 3.1.1. This is due to the firebase_auth() function authenticating the request as the WordPress user whose email is supplied in the user_email POST parameter without verifying ownership of that email (no Firebase ID token signature/issuer/audience verification). This makes it possible for authenticated attackers, with Subscriber-level access and above, to log in as an arbitrary existing user — including an Administrator — by submitting that user's email address to the acb_firebase_auth AJAX action, resulting in full account takeover.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H8.8/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HConfiguration