CVE-2017-0881
An error in the implementation of an autosubscribe feature in the check_stream_exists route of the Zulip group chat application server before 1.4.3 allowed an authenticated user to subscribe to a private stream that should have required an invitation from an existing member to join. The issue affects all previously released versions of the Zulip server.
Date published : 2017-03-27
http://www.securityfocus.com/bid/97159
https://github.com/zulip/zulip/commit/7ecda1ac8e26d8fb3725e954b2dc4723dda2255f