Description
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.
Remediation
References
http://www.openwall.com/lists/oss-security/2016/12/22/12
http://www.securityfocus.com/bid/95129
https://community.igniterealtime.org/blogs/ignite/2016/11/22/smack-security-advisory-2016-11-22
https://github.com/igniterealtime/Smack/commit/059ee99ba0d5ff7758829acf5a9aeede09ec820b
https://github.com/igniterealtime/Smack/commit/a9d5cd4a611f47123f9561bc5a81a4555fe7cb04
https://issues.igniterealtime.org/projects/SMACK/issues/SMACK-739
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J4WXAZ4JVJXHMEDDXJVWJHPVBF5QCTZF/