What is the MOST effective measure to mitigate vulnerabilities in an outdated process control terminal?

Application whitelisting is the most effective measure to mitigate vulnerabilities in an outdated process control terminal because it controls which applications are allowed to run on the system. By implementing application whitelisting, only pre-approved software can be executed, significantly reducing the risk of exploitation by malicious software or unauthorized applications. This is particularly important in environments where the software may not receive regular updates, as it can help protect against vulnerabilities that could be exploited by attackers.

In contrast, the other options focus on different types of cybersecurity measures that may not be as effective in addressing the specific challenges posed by old and outdated processes. For example, DNS sinkholing redirects malicious traffic but does not address vulnerabilities within the terminal itself. Data Loss Prevention (DLP) rules on the terminal are designed to protect sensitive data and may not prevent attackers from exploiting vulnerabilities. An IP blacklist might restrict known sources of malicious traffic, but it does not prevent the execution of harmful applications that may already be present or can still access the system through other means.