An organization has recently hired a large number of part-time employees. During the annual audit, it was discovered that many user IDs and passwords were documented in procedure manuals for use by…

A threat is a potential cause of an unwanted incident (e.g., an attacker), but the situation itself of shared credentials isn't the threat; it's the weakness that a threat could exploit.

A risk is the potential for loss, damage, or destruction of an asset as a result of a threat exploiting a vulnerability. In this scenario, documenting shared user IDs and passwords in procedure manuals for part-time employees introduces a vulnerability (lack of individual accountability and control over credentials) that can be exploited by a threat (e.g., a disgruntled employee, unauthorized access, or loss of manuals), leading to a negative impact on organizational assets. Therefore, this situation defines a clear risk to the organization.

A vulnerability is a weakness in a system or design (e.g., the shared password itself), but the entire described situation encompasses both the weakness and the potential negative outcome, making it a risk.

A policy violation might be an underlying cause or consequence, but 'policy violation' doesn't fully capture the security implications and potential for harm inherent in the situation as 'risk' does.