The server in Toribash 2.71 and earlier does not properly handle partially joined clients that are temporarily assigned the ID of -1, which allows remote attackers to cause a denial of service (daemon crash) via a GRIP command with the ID of -1.
https://exchange.xforce.ibmcloud.com/vulnerabilities/36098
http://www.securityfocus.com/archive/1/477025/100/0/threaded