WAF - WAF Release - 2025-12-01

This week’s release introduces new detections for remote code execution attempts targeting Monsta FTP (CVE-2025-34299), alongside improvements to an existing XSS detection to enhance coverage. Key Findings CVE-2025-34299 is a critical remote code execution flaw in Monsta FTP, arising from improper handling of user-supplied parameters within the file-handling interface. Certain builds allow crafted requests to bypass sanitization and reach backend PHP functions that execute arbitrary commands. Attackers can send manipulated parameters through the web panel to trigger command execution within the application’s runtime environment. Impact If exploited, the vulnerability enables full remote command execution on the underlying server, allowing takeover of the hosting environment, unauthorized file access, and potential lateral movement. As the flaw can be triggered without authentication on exposed Monsta FTP instances, it represents a severe risk for publicly reachable deployments. Ruleset Rule ID Legacy Rule ID Description Previous Action New Action Comments Cloudflare Managed Ruleset 480da5e7984542a6b8d8d88da4fcc8a8 N/A Monsta FTP - Remote Code Execution - CVE:CVE-2025-34299 Log Block This is a new detection Cloudflare Managed Ruleset 2380b125c53d42ac94479c42b7492846 N/A XSS - JS Context Escape - Beta Log Block This rule is merged into the original rule "XSS - JS Context Escape" (ID: c1ad1bc37caa4cbeb104f44f7a3769d3 )