The Chief Information Officer (CIO) asked a vendor to provide documentation detailing the specific objectives within the compliance framework that the vendor's services meet. The vendor provided a report and a signed letter stating that the services meet 17 of the 21 objectives. Which of the following did the vendor provide to the CIO?

An attestation of compliance is a formal statement, often a signed letter, from a vendor or third party confirming that their services or systems meet specific compliance objectives or standards. In this scenario, the vendor provided a report and a signed letter detailing which objectives their services meet, directly aligning with the definition of an attestation. Penetration test results would detail vulnerabilities found during a simulated attack, not compliance objectives. Self-assessment findings are internal evaluations, not typically provided as a formal, signed statement to a client regarding compliance. A third-party audit report would involve an independent auditor's detailed examination and opinion, which is more extensive and formal than what was described.