GHSA-66hx-chf7-3332 pyLoad has Stale Session Privilege After Role/Permission Change (Privilege Revocation Bypass)

• PyPI pyload-ng: <= 0.5.0b3.dev97 (no fix yet)

Summary pyLoad caches `role` and `permission` in the session at login and continues to authorize requests using these cached values, even after an admin changes the user's role/permissions in the database. As a result, an already logged-in user can keep old (revoked) privileges until logout/session expiry, enabling continued privileged actions. This is a core authorization/session-consistency issue and is not resolved by toggling an optional security feature. Details The WebUI auth flow stores authorization state in session: • `src/pyload/webui/app/helpers.py:187-200` • `set_session(...)` writes: • `"role": user_info["role"]` • `"perms": user_info["permission"]` Authorization checks later trust cached session values: • `src/pyload/webui/app/helpers.py:134-151` • `parse_permissions(...)` reads `session.get("role")` / `session.get("perms")` • `src/pyload/webui/app/helpers.py:225-230` • `is_authenticated(...)` only verifies `authenticated` and `api.user_exists(user)` (existence), not fresh role/permission • `src/pyload/webui/app/helpers.py:267-275` • `login_required(...)` uses `parse_permissions(s)` for allow/deny decisions • `src/pyload/webui/app/helpers.py:356-365` • API session auth path also trusts `s["role"]` and `s["perms"]` Role/permission updates are written to DB but active sessions are not invalidated/refreshed: • `src/pyload/webui/app/blueprints/json_blueprint.py:389-434` • `update_users(...)` calls `api.set_user_permission(...)` and returns • `src/pyload/core/api/__init__.py:1643-1645` • `set_user_permission(...)` updates DB role/permission only Default exposure window is long: • `src/pyload/core/config/default.cfg:47` • `session_lifetime = 44640` minutes (~31 days) Therefore, privilege revocation is not enforced immediately for active sessions. Note on duplicates: • This appears distinct from CVE-2023-0227 (session validity after user deletion) because this report is about stale authorization after role/permission changes while the user still exists. PoC ```python !/usr/bin/env python3 """ Repro: stale session privilege after role/permission changes. This PoC is source-based and leaves no persistent state. It validates that: 1) Role/permission are cached into session at login. 2) Authorization checks read role/permission from session, not fresh DB values. 3) User updates write DB permission/role without invalidating active sessions. 4) Default session lifetime is long, increasing stale-privilege exposure window. """ from __future__ import annotations import pathlib import re from typing import Iterable ROOT = pathlib.Path(__file__).resolve().parent / "pyload" / "src" / "pyload" def read(rel: str) -> str: return (ROOT / rel).read_text(encoding="utf-8") def has_any(text: str, patterns: Iterable[str]) -> bool: return all(re.search(p, text, re.MULTILINE) for p in patterns) def main() -> None: helpers = read("webui/app/helpers.py") json_blueprint = read("webui/app/blueprints/json_blueprint.py") api_init = read("core/api/__init__.py") default_cfg = (ROOT / "core/config/default.cfg").read_text(encoding="utf-8") checks = { "set_session_caches_role_perms": has_any( helpers, [ r'def\\s+set_session\\(', r'"role"\\s*:\\s*user_info\\["role"\\]', r'"perms"\\s*:\\s*user_info\\["permission"\\]', ], ), "is_authenticated_only_checks_user_exists": has_any( helpers, [ r'def\\s+is_authenticated\\(', r'api\\s*=\\s*flask\\.current_app\\.config\\["PYLOAD_API"\\]', r'return\\s+authenticated\\s+and\\s+api\\.user_exists\\(user\\)', ], ), "parse_permissions_reads_session_cache": has_any( helpers, [ r'def\\s+parse_permissions\\(', r'session\\.get\\("role"\\)\\s*==\\s*Role\\.ADMIN', r'session\\.get\\("perms"\\)', ], ), "login_required_uses_parse_permissions_session": has_any( helpers, [ r'def\\s+login_required\\(', r'if\\s+is_authenticated\\(s\\):', r'perms\\s*=\\s*parse_permissions\\(s\\)', ], ), "api_session_auth_uses_cached_role_perms": has_any( helpers, [ r'if\\s+is_authenticated\\(s\\):', r'"role"\\s*:\\s*s\\["role"\\]', r'"permission"\\s*:\\s*s\\["perms"\\]', ], ), "update_users_changes_db_without_session_invalidation": has_any( json_blueprint, [ r'def\\s+update_users\\(', r'api\\.set_user_permission\\(name,\\s*data\\["permission"\\],\\s*data\\["role"\\]\\)', r'return\\s+jsonify\\(True\\)', ], ), "set_user_permission_only_updates_db": has_any( api_init, [ r'def\\s+set_user_permission\\(', r'self\\.pyload\\.db\\.set_permission\\(user,\\s*permission\\)', r'self\\.pyload\\.db\\.set_role\\(user,\\s*role\\)', ], ), "default_session_lifetime_long": re.search( r'session_lifetime\\s*:\\s*"Session lifetime \\(minutes\\)"\\s*=\\s*44640', default_cfg, re.MULTILINE, ) is not None, } for name, ok in checks.items(): print(f"{name}={ok}") stale_privilege_repro_success = all(checks.values()) print(f"stale_privilege_repro_success={stale_privilege_repro_success}") # Cleanup: this PoC creates/modifies no runtime/data files. print("cleanup_done=True") if __name__ == "__main__": main() ``` ```text set_session_caches_role_perms=True is_authenticated_only_checks_user_exists=True parse_permissions_reads_session_cache=True login_required_uses_parse_permissions_session=True api_session_auth_uses_cached_role_perms=True update_users_changes_db_without_session_invalidation=True set_user_permission_only_updates_db=True default_session_lifetime_long=True stale_privilege_repro_success=True cleanup_done=True ``` Impact • Privilege revocation is not immediate for active sessions. • A user can continue using stale, previously granted privileges (including admin) after downgrade/restriction. • This can allow continued access to privileged WebUI/API actions until session expiry or manual logout/session reset.