Race condition in the XMPP library in Smack before 4.1.9, when the SecurityMode.required TLS setting has been set, allows man-in-the-middle attackers to bypass TLS protections and trigger use of cleartext for client authentication by stripping the "starttls" feature from a server response.
The ServerTrustManager component in the Ignite Realtime Smack XMPP API before 4.0.0-rc1 does not verify basicConstraints and nameConstraints in X.509 certificate chains from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate chain.
The ParseRoster component in the Ignite Realtime Smack XMPP API before 4.0.0-rc1 does not verify the from attribute of a roster-query IQ stanza, which allows remote attackers to spoof IQ responses via a crafted attribute.