Executive brief
OpenClaw is a gateway and authentication system used to manage API access and WebSocket connections. An attacker can bypass rate limiting on shared authentication attempts by submitting fake device tokens alongside legitimate authentication requests, potentially enabling brute-force attacks against weak shared secrets. This risk is most significant for deployments relying on shared passwords rather than strong cryptographic tokens.
Technical details
The vulnerability exists in OpenClaw's WebSocket handshake authentication handler, where the presence of a device-token field in the request (even with a bogus value) causes the shared-auth rate limiting mechanism to be bypassed. The root cause is insufficient validation—the gateway fails to enforce rate limits on shared-secret brute-force attempts when callers also provide device-token candidates during mixed handshake flows. An attacker can exploit this with only network access and no authentication prerequisites. The impact is limited to brute-force facilitation against weak shared passwords; strong cryptographic tokens remain non-bruteforceable. A fix is available in version 2026.3.31 (commit af0c086), which preserves shared-auth rate limiting during mixed WebSocket handshakes.
Affected products
- OpenClaw OpenClaw <=2026.3.28
Timeline
- 2026-04-03: disclosed
- 2026-03-31: patched: Fix available in version 2026.3.31