Executive brief
OpenClaw is a voice-call management platform that processes Twilio webhook events to handle incoming calls. A flaw in how the platform deduplicates webhook events allows attackers to replay legitimate Twilio events multiple times, causing the system to process the same call event repeatedly. This can result in incorrect call state transitions, corrupted call records, and unpredictable voice-call behavior affecting users relying on accurate call handling.
Technical details
The vulnerability is a capture-replay authentication bypass (CWE-294) in OpenClaw's Twilio webhook event deduplication logic. The root cause is that normalized event IDs are randomized on each parse, preventing the deduplication manager from reliably identifying replayed events. An attacker can intercept and re-send legitimate Twilio webhook events to the OpenClaw platform; because the dedupe check fails, replay events bypass the manager's replay detection and are treated as new events. This allows duplicate or stale call-state transitions to be executed, corrupting call state. The fix (released in 2026.2.23) preserves provider event IDs through normalization, adds bounded replay dedupe in webhook security validation, and enforces per-call turn-token checks on state transitions. The vulnerability requires network access to the webhook endpoint but no authentication.
Affected products
- OpenClaw openclaw < 2026.2.23
Timeline
- 2026-02-24: disclosed: Advisory published; reported by jiseoung
- 2026-02-24: patched: Fix released in version 2026.2.23
- 2026-03-21: advisory: GHSA-3r78-rqg8-95gg published (later withdrawn as duplicate)
- 2026-03-24: withdrawn: GHSA-3r78-rqg8-95gg withdrawn; duplicates GHSA-vqx8-9xxw-f2m7