 HOFFMAN ESTATES, Ill.--BUSINESS WIRE--CDK Global, Inc. Nasdaq: CDK, a leading retail automotive technology company, announced today that David Hahn has joined the company as chief information security officer CISO. He will also be a member of the executive leadership team. In his role, Hahn is responsible for developing a global strategy and executing the roadmap for managing technology risk and information security across the companys IT, product engineering, and research and developmen 