First isolate to prevent further damage, then analyse root cause.

Cross-Domain Misconfiguration suggests that there might be an issue related to how the web application handles cross-origin requests.
Configuring an Access-Control-Allow-Origin header allows the server to specify which domains are permitted to access its resources, thereby controlling access to resources from different origins.
By configuring the Access-Control-Allow-Origin header to authorize specific domains, the organization can mitigate the risk of unauthorized cross-origin access and prevent potential security vulnerabilities associated with cross-domain interactions..

A vulnerability scan is a process of identifying and assessing the security weaknesses of a system or network. A vulnerability scan can help a security analyst to effectively identify the most security risks associated with a locally hosted server, such as missing patches, misconfigurations, outdated software, or exposed services. A vulnerability scan can also provide recommendations on how to remediate the identified vulnerabilities and improve the security posture of the server.

The Diamond Model of Intrusion Analysis is a framework that describes the relationship between four components of a cyberattack: adversary, capability, infrastructure, and victim. It helps analysts understand the behavior and motivation of threat actors, as well as the tools and methods they use to compromise their targets.