FriendsOfFlarum OAuth: Unauthenticated account takeover via unverified email trust in Discord OAuth provider
An unauthenticated account takeover vulnerability exists in fof/oauth when the Discord OAuth provider is enabled. Discord allows an account to use an unverified email address when its phone number has been verified. During OAuth authentication, Discord may return that email address with "verified": false. Affected versions of fof/oauth did not validate this flag and passed the email address to Flarum core as trusted via provideTrustedEmail(). Flarum core could then match …