A Twilio webhook signature-verification bypass in the voice-call extension could allow unauthenticated webhook requests when a specific ngrok free-tier compatibility option is enabled.
This issue is limited to configurations that explicitly enable and expose the voice-call webhook endpoint.
Not affected by default:
- The voice-call extension is optional and disabled by default.
- The bypass only applied when tunnel.allowNgrokFreeTierLoopbackBypass was explicitly enabled.
- Exploitation required the webhook to be reachable (typically via a public ngrok URL during development).
Worst case (when exposed and the option was enabled):
- An external attacker could send forged requests to the publicly reachable webhook endpoint that would be accepted without a valid X-Twilio-Signature.
- This could result in unauthorized webhook event handling (integrity) and request flooding (availability).
openclaw (npm)<= 2026.2.13 (latest published as of 2026-02-14)>= 2026.2.14 (planned next release; pending publish)allowNgrokFreeTierLoopbackBypass no longer bypasses signature verification. It only enables trusting forwarded headers on loopback so the public ngrok URL can be reconstructed for correct signature validation.
Fix commit(s): - ff11d8793b90c52f8d84dae3fbb99307da51b5c9
Thanks @p80n-sec for reporting.
{
"nvd_published_at": null,
"github_reviewed_at": "2026-02-18T00:54:48Z",
"github_reviewed": true,
"severity": "MODERATE",
"cwe_ids": [
"CWE-306"
]
}