You finished a penetration test that identified a web server with a critical vulnerability. The web server's role is mission critical to your organization and has an uptime requirement of $99\mathrm{.}9$ percent. If you patch the vulnerability, it may break the application running on this server. How do you secure the web server until another solution is found?

Question $4$ options:

Installing antivirus protection

Via a HIDS$/$HIPS

Using a circuit$-$level gateway

Using a stateful inspection firewall