Description

Active sessions are not invalidated after a password change or after an admin resets the user's password.

Proof of Concept

Steps to reproduce:

1. Log in to Elgg with any user
2. Do the same in another browser or a private window, such that there are two different active sessions
3. Update the user's password in either of the two sessions
4. Observe that the other session is still active and was not invalidated

This issue also exists when an admin changes or resets an account's password.

Impact

An old session can be used by an attacker even after the password has been changed or reset. A password change is a way to react to an account breach and should guarantee that the attacker no longer has access. However, in this case the session is still active and the attacker can perform all actions tied to that session until it expires.