An authentication issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.6.5, macOS Monterey 12.3, Security Update 2022-003 Catalina. A local attacker may be able to view the previous logged in user’s desktop from the fast user switching screen.
CWE-287 - Improper Authentication
Improper (or broken) authentication attacks are widespread, and have accounted for many of the worst data breaches in recent years. Improper authentication attacks are a class of vulnerabilities where an attacker impersonates a legitimate user by exploiting weaknesses in either session management or credential management to gain access to the user’s account. This can result in disclosure of sensitive information, and can lead to system compromise, theft, identity theft, and fraud.