OpenClaw versions prior to 2026.2.14 contain a webhook signature-verification bypass in the voice-call extension that allows unauthenticated requests when the tunnel.allowNgrokFreeTierLoopbackBypass option is explicitly enabled. An external attacker can send forged requests to the publicly reachable webhook endpoint without a valid X-Twilio-Signature header, resulting in unauthorized webhook event handling and potential request flooding attacks.
CWE-306