This also requires the install media but like I mentioned just try one see if it errors and tells you the version you want.
Switch to local authentication
In the event that an element belongs to the UCM security domain and access to the Primary
or Secondary UCM Security Server is interrupted, or a device is removed from the security
domain, users with network administrator permissions can still access local elements using
local authentication and authorization methods.
To reset authentication to local, follow the steps in Switching to local authentication on
page 260.
Switching to local authentication
1. At the device CLI, enter CTRL-P, CTRL-D, CTRL-T to start PDT.
Do not enter your UserID at the prompt.
2. At the prompt, enter the authentication reset command:
resetCAUTH
The authentication reset initiates and a message appears stating that you must load
the installation media into the removable media drive within 60 seconds.
3. Load the installation media into the removable media drive.
Once the installation media is confirmed, the authentication type is set to LOCAL.
4. Remove the installation media and, if prompted, insert any backup media.
To rejoin a device to the UCM security domain, you must issue the appropriate command, as
described in Add or remove elements from the UCM security domain on page 237.