Big Sur - Disable iCloud Keychain Sync

Information

The macOS system's ability to automatically synchronize a user's passwords to their iCloud account _MUST_ be disabled.

Apple's iCloud service does not provide an organization with enough control over the storage and access of data and, therefore, password management and synchronization _MUST_ be controlled by an organization approved service.

Solution

This is implemented by a Configuration Profile.

mobileconfig profile info:

com.apple.applicationaccess:
allowCloudKeychainSync:
False

See Also

https://github.com/usnistgov/macos_security