FAR 52.204-21
Basic Safeguarding of Covered Contractor Information Systems
What it says
Imposes 15 basic cyber hygiene requirements (access control, patching, malware protection, etc.) on contractor systems that process federal contract information.
Why it matters on DIBBS
The cyber floor for every federal contractor, including pure suppliers. The 15 controls are things a competent IT setup does anyway — but you are certifying them, so check.