prosody before versions 0.10.2, 0.9.14 is vulnerable to an Authentication Bypass. Prosody did not verify that the virtual host associated with a user session remained the same across stream restarts. A user may authenticate to XMPP host A and migrate their authenticated session to XMPP host B of the same Prosody instance.

An issue was discovered in Prosody before 0.11.9. The undocumented dialbackwithoutdialback option in moddialback enables an experimental feature for server-to-server authentication. It does not correctly authenticate remote server certificates, allowing a remote server to impersonate another server (when this option is enabled).