Executive brief
OpenClaw is a voice-calling library that integrates with Twilio webhooks to manage call state. A flaw in event deduplication logic allows replayed webhook events to bypass security checks because event IDs are randomized during normalization, treating replayed events as new calls. An attacker could trigger duplicate or stale call-state transitions, potentially causing call-handling inconsistencies or disrupting legitimate call flows.
Technical details
OpenClaw's voice-call manager uses webhook event deduplication to prevent processing duplicate Twilio webhook events, but the normalized event IDs are randomized on each parse, breaking idempotency. This is a capture-replay vulnerability (CWE-294) combined with incorrect authorization (CWE-863): a replayed Twilio webhook passes the manager dedupe check because the normalized event ID differs each time, even though the provider event ID is the same. The vulnerability requires network access to intercept and replay webhooks, with no authentication or user interaction required. An attacker can resend previously captured Twilio webhook events to cause duplicate or stale call-state transitions. The fix (version 2026.2.23+) preserves provider event IDs through normalization, adds bounded replay dedupe in webhook validation, and enforces per-call turn-token checks on state transitions.
Affected products
- OpenClaw openclaw <= 2026.2.22-2
Timeline
- 2026-03-03: disclosed: Advisory published
- 2026-02-24: patched: Patch released as version 2026.2.23