WAF - WAF Release - 2025-11-05 - Emergency

This week’s emergency release introduces a new detection signature that enhances coverage for a critical vulnerability in the React Native Metro Development Server, tracked as CVE-2025-11953. Key Findings The Metro Development Server exposes an HTTP endpoint that is vulnerable to OS command injection (CWE-78). An unauthenticated network attacker can send a crafted request to this endpoint and execute arbitrary commands on the host running Metro. The vulnerability affects Metro/cli-server-api builds used by React Native Community CLI in pre-patch development releases. Impact Successful exploitation of CVE-2025-11953 may result in remote command execution on developer workstations or CI/build agents, leading to credential and secret exposure, source tampering, and potential lateral movement into internal networks. Administrators and developers are strongly advised to apply the vendor's patches and restrict Metro’s network exposure to reduce this risk. Ruleset Rule ID Legacy Rule ID Description Previous Action New Action Comments Cloudflare Managed Ruleset db6b9e1ac1494971ae8c70aac8e30c5b N/A React Native Metro - Command Injection - CVE:CVE-2025-11953 N/A Block This is a New Detection