Which of the following describes a situation where a user is authorized before being authenticated?

Impersonation occurs when an attacker or unauthorized user is granted access (authorized) by masquerading as a legitimate user, effectively bypassing or exploiting the authentication process. This means authorization is mistakenly granted before proper authentication.

Privilege escalation (A) involves gaining higher access after authentication. Race conditions (B) are timing vulnerabilities. Tailgating (C) refers to physical unauthorized access by following an authorized person.

Impersonation is a well-known identity attack vector detailed in the Threats and Vulnerabilities domain of SY0-701【6:Chapter 4†CompTIA Security+ Study Guide】.