Turn off access to the CLI

Hi All,
Due to some cause we have to turned off the access of Jenkins CLI.
Please guide us how to do that and what would be the impact to turned of CLI.
Required is ASAP.

Thanks

Detailed instructions are available in the security advisory at:

The best choice is to upgrade to Jenkins 2.426.3 (LTS) or Jenkins 2.442 (weekly). However, if you can’t upgrade, then disabling the command line interface is a reasonable short-term measure while you prepare for and complete the upgrade to Jenkins 2.426.3 (LTS) or Jenkins 2.442 (weekly).

A video demonstration of the technique is available from Darin Pope at:

When I tried running the second groovy script which don’t even start the jenkins CLI post restart is not working.
Please guide me on how to fix it…

Finally I got to know we need to run both the scripts 1 and 2nd script from kb disable jenkins cli.
which will suffice post restart not just 2nd script