Description
Apostrophe CMS versions prior to 3.3.1 did not invalidate existing login sessions when disabling a user account or changing the password, creating a situation in which a device compromised by a third party could not be locked out by those means. As a mitigation for older releases the user account in question can be archived (3.x) or moved to the trash (2.x and earlier) which does disable the existing session.
Remediation
References
https://github.com/apostrophecms/apostrophe/commit/c211b211f9f4303a77a307cf41aac9b4ef8d2c7c