| Package | Affected versions | Patched versions |
|---|---|---|
| openclaw | < 2026.2.19 | 2026.2.19 |
| openclaw | < 2026.2.19 | 2026.2.19 |
ZDI-CAN-29311: OpenClaw Canvas Authentication Bypass Vulnerability
-- ABSTRACT -------------------------------------
Trend Micro's Zero Day Initiative has identified a vulnerability affecting the following products: OpenClaw - OpenClaw
-- VULNERABILITY DETAILS ------------------------
The OpenClaw gateway's authorizeCanvasRequest() function implements an IP-based authentication fallback for canvas endpoints (/__openclaw__/a2ui/, /__openclaw__/canvas/, /__openclaw__/ws). When a WebSocket client authenticates from a private IP address, ALL subsequent HTTP requests from that same IP are granted canvas access without requiring their own authentication token.
In environments where multiple clients share a single IP address ��� corporate NAT, VPN concentrators, Kubernetes clusters, Docker host-mode networking ��� an unauthenticated attacker on the same network is granted full canvas access by virtue of sharing an IP with a legitimate authenticated client.
Three functions in src/gateway/server-http.ts create this vulnerability:
function hasAuthorizedWsClientForIp(clients: Set<GatewayWsClient>, clientIp: string): boolean {
for (const client of clients) {
if (client.clientIp && client.clientIp === clientIp) {
return true;
}
}
return false;
}
This function checks if ANY connected WebSocket client shares the same IP. It does not verify that the HTTP request belongs to the same user, session, or browser as the WS client.
async function authorizeCanvasRequest(params: { ... }): Promise<GatewayAuthResult> {
// ... token check first ...
const clientIp = resolveGatewayClientIp({ ... });
// Only allow fallback for private/loopback addresses
if (!isPrivateOrLoopbackAddress(clientIp)) {
return lastAuthFailure ?? { ok: false, reason: "unauthorized" };
}
// THE VULNERABILITY: grants access based on IP alone
if (hasAuthorizedWsClientForIp(clients, clientIp)) {
return { ok: true };
}
return lastAuthFailure ?? { ok: false, reason: "unauthorized" };
}
If the HTTP request comes from a private IP that matches any authenticated WS client, access is granted without verifying the request's own credentials.
function isCanvasPath(pathname: string): boolean {
return (
pathname === A2UI_PATH || // /__openclaw__/a2ui
pathname.startsWith(`${A2UI_PATH}/`) ||
pathname === CANVAS_HOST_PATH || // /__openclaw__/canvas
pathname.startsWith(`${CANVAS_HOST_PATH}/`) ||
pathname === CANVAS_WS_PATH // /__openclaw__/ws
);
}
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site freeAll canvas endpoints use this weaker authentication path instead of the standard authorizeGatewayConnect() which requires a valid token.
--bind lan and a token for authentication.10.0.0.1).10.0.0.1 to the gateway (NAT).http://gateway:18789/__openclaw__/a2ui/ with NO authentication header.authorizeCanvasRequest() checks: Is 10.0.0.1 a private IP? Yes. Is there a WS client from 10.0.0.1? Yes (Alice). Access granted.In containerized deployments using shared networking (host mode, pod networking), multiple containers share the same IP. One container's authentication enables canvas access for all containers on that IP.
openclaw:localNavigate to the PoC directory and start the environment:
cd vulnerabilities/04-canvas-ip-auth-bypass
docker compose up -d --wait
This starts two containers on a shared Docker network:
Wait a few seconds for the legitimate client to authenticate, then run the PoC:
python3 poc.py
The PoC runs three tests:
| Test | Source | Source IP | Token | Result |
|---|---|---|---|---|
| 1 ��� Host (different IP) | Host machine | Host bridge IP | None | 401 Unauthorized |
| 2 ��� Host with token (control) | Host machine | Host bridge IP | Valid | 200 OK |
| 3 ��� Same IP (exploit) | docker exec into legit container | 172.28.0.20 | None | 200 OK |
Test 3 is the exploit: poc.py uses docker exec to run an HTTP request from inside the legitimate client's container (IP 172.28.0.20) with no Authorization header. The gateway's authorizeCanvasRequest() matches the source IP against the authenticated WebSocket client and returns 200 OK ��� granting full canvas access without credentials.
Cleanup:
docker compose down -v
--bind lan) and clients share IP addresses (NAT, VPN, K8s, corporate networks).-- CREDIT --------------------------------------- This vulnerability was discovered by: Peter Girnus (@gothburz) and Project AESIR of TrendAI Zero Day Initiative
-- FURTHER DETAILS ------------------------------
Supporting files: ZDI-CAN-29311.zip
If supporting files were contained with this report they are provided within a password protected ZIP file. The password is the ZDI candidate number in the form: ZDI-CAN-XXXX where XXXX is the ID number.
Zero Day Initiative [email protected]
The PGP key used for all ZDI vendor communications is available from:
-- INFORMATION ABOUT THE ZDI -------------------- Established by TippingPoint and acquired by Trend Micro, the Zero Day Initiative (ZDI) neither re-sells vulnerability details nor exploit code. Instead, upon notifying the affected product vendor, the ZDI provides its Trend Micro TippingPoint customers with zero day protection through its intrusion prevention technology. Explicit details regarding the specifics of the vulnerability are not exposed to any parties until an official vendor patch is publicly available.
Please contactZero Day Initiative for further details or refer to:
-- DISCLOSURE POLICY ----------------------------
Zero Day Initiative's vulnerability disclosure policy is available online at:
c45f3c5b004c8d63dc0e282e2176f8c9355d24f1