An ANSI escape sequence vulnerability (CVE-2017-0899).
A DoS vulnerability in the query command (CVE-2017-0900).
A vulnerability in the gem installer that allowed a malicious gem to overwrite arbitrary files (CVE-2017-0901).
A DNS request hijacking vulnerability (CVE-2017-0902).
An unsafe object deserialization vulnerability that allows an attacker to inject an instance of an object of their choosing in the target system. A clever attacker can inject an object that is able to interact with the system in such a way that will allow the attacker to execute arbitrary code (CVE-2017-0903).