This detection rule aims to identify and block Remote Code Execution (RCE) attempts exploiting the React2Shell vulnerability (CVE-2025-55182) within Cloudflare's Firewall Management System. It operates by scrutinizing incoming traffic and evaluating HTTP requests against known behaviors associated with the vulnerability, particularly looking for patterns that suggest malicious attempts to execute arbitrary code. The rule leverages metadata from the incoming requests, such as the client’s IP address, country, and user-agent, to establish a baseline of legitimate versus potentially malicious behavior. When a request matches the configured criteria, it triggers an automatic block action to mitigate threats before they can penetrate the protected system. The rule emphasizes the necessity of prompt investigation by querying firewall logs for related activity surrounding detection events, and highlights the importance of identifying any similar attempts from the same source within a specified time frame.