The generate_dialback function in the mod_dialback module in Prosody before 0.9.10 does not properly separate fields when generating dialback keys, which allows remote attackers to spoof XMPP network domains via a crafted stream id and domain name that is included in the target domain as a suffix.
Debian Linux Security Advisory 3463-1 - It was discovered that insecure handling of dialback keys may allow a malicious XMPP server to impersonate another server.