A Security Assessor Completed a Comprehensive Penetration Test of a Company

A security assessor completed a comprehensive penetration test of a company and its networks and systems. During the assessment, the tester identified a vulnerability in the crypto library used for TLS on the company's intranet-wide payroll web application. However, the vulnerability has not yet been patched by the vendor, although a patch is expected within days. Which of the following strategies would BEST mitigate the risk of impact?

A) Modify the web server crypto configuration to use a stronger cipher-suite for encryption, hashing, and digital signing.
B) Implement new training to be aware of the risks in accessing the application. This training can be decommissioned after the vulnerability is patched.
C) Implement an ACL to restrict access to the application exclusively to the finance department. Reopen the application to company staff after the vulnerability is patched.
D) Require payroll users to change the passwords used to authenticate to the application. Following the patching of the vulnerability, implement another required password change.