Vino 2.28, 2.32, 3.4.2, and earlier allows remote attackers to read clipboard activity by listening on TCP port 5900.
https://exchange.xforce.ibmcloud.com/vulnerabilities/78602
http://www.ubuntu.com/usn/USN-1701-1
http://www.securityfocus.com/bid/55548
http://www.openwall.com/lists/oss-security/2012/09/14/1
http://www.openwall.com/lists/oss-security/2012/09/13/25