The PUT /api/v2/users/{user}/password endpoint authorized only ActionUpdatePersonal and did not prevent a user-admin from resetting an owner account's password. It also did not require the current password when an admin reset another user's password.
Note: Exploitation requires the privileged user-admin role so practical risk is limited to deployments that grant user-admin to less trusted operators.
Impact
A user-admin could reset any owner's password without knowing it, authenticate as that owner and gain full deployment control, including templates, workspaces, licensing, organization settings and the ability to self-assign the owner role. This was a privilege escalation from user-admin to owner.
Patches
The fix prevents non-owner users from resetting the password of an account that holds the owner role.
The fix was backported to all supported release lines: