Given the vulnerability in the deprecated runtime engine, configuring an IPS (Intrusion Prevention System) and WAF (Web Application Firewall) with appropriate signatures is the best temporary control. This allows the organization to monitor and block potential attacks targeting known vulnerabilities in the runtime engine while the developers work on the transition. Shutting down the systems or uninstalling the runtime engine would cause service interruptions, and blocking traffic might disrupt legitimate users. IPS and WAF provide an active layer of defense without interrupting service. CASP+ emphasizes the use of layered security, including IPS and WAF, to mitigate risks in public-facing applications.
References:
* CASP+ CAS-004 Exam Objectives: Domain 3.0 - Enterprise Security Architecture (Web Application Firewalls, Intrusion Prevention Systems)
* CompTIA CASP+ Study Guide: Mitigating Application Vulnerabilities with WAFs and IPS