Vasiliy Kulikov reported  that obby does not check a server's SSL certificate when connecting. It also sends the password in plaintext form over the SSL channel. An attacker able to perform a MITM attack on the connection could easily do so without discovery due to obby not checking the server's SSL certificate.
Note: if the client is Gobby, the reconnection attempt will require user interaction.
Upstream has indicated  that it is not worth the effort to implement SSL certificate checking in obby as it is deprecated by libinfinity, which is used by the development version of Gobby, so there is currently no fix for obby.
Created obby tracking bugs for this issue
Affects: fedora-all [bug 750641]
Affects: epel-all [bug 750642]