9Router: Mass assignment in PATCH /api/settings allows authenticated authorization downgrade

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9Router is an AI router & token saver. Prior to 0.5.4, the PATCH /api/settings endpoint writes the entire request body to persistent settings without a field whitelist, allowing an authenticated user to set security-critical fields such as requireLogin and disable authentication for the whole application, exposing protected routes such as /api/keys and /api/providers to unauthenticated access. This issue is reported as fixed in version 0.5.4.

Source published

15 Jul 2026 20:50:30 UTC

Source modified

16 Jul 2026 13:00:42 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

9Router is an AI router & token saver. Prior to 0.5.4, the PATCH /api/settings endpoint writes the entire request body to persistent settings without a field whitelist, allowing an authenticated user to set security-critical fields such as requireLogin and disable authentication for the whole application, exposing protected routes such as /api/keys and /api/providers to unauthenticated access. This issue is reported as fixed in version 0.5.4.

Source published

15 Jul 2026 21:16:55 UTC

Source modified

24 Oct 2026 21:10:00 UTC

Observed here

25 Oct 2026 14:19:10 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

### Summary The `PATCH /api/settings` endpoint writes the entire request body to persistent settings without a field whitelist. An authenticated user can set security-critical fields that are not meant to be modifiable here — notably `requireLogin`. Setting `requireLogin: false` disables authentication for the whole application, exposing all protected routes (e.g. `/api/keys`, `/api/providers`) to unauthenticated access. ### Details Root cause is unfiltered mass assignment (CWE-915): - `src/app/api/settings/route.js` (PATCH handler) parses the body and passes it to `updateSettings(body)`, with special handling only for `newPassword` and `oidcClientSecret`. All other fields pass through. - `src/lib/db/repos/settingsRepo.js` — `updateSettings` does `next = { ...current, ...updates }`, so any key in the body overwrites stored settings, including `requireLogin`, `tunnelDashboardAccess`, `authMode`. - `src/dashboardGuard.js` — `isAuthenticated` returns `true` whenever `settings.requireLogin === false`, bypassing auth on all protected routes. This is distinct from CVE-2026-5842 (CWE-285, pre-auth bypass on `/api`, patched in 0.3.75). This finding requires a valid authenticated session and abuses input handling, not missing authentication. ### PoC Instance on `localhost:20128`, default password `123456`. 1. Authenticate, capture session: `POST /api/auth/login` body `{"password":"123456"}` → `200 {"success":true}` 2. Mass-assign with the authenticated session: `PATCH /api/settings` body `{"requireLogin":false}` → `200`, response confirms `"requireLogin":false` 3. Verify bypass with NO session/credentials: `GET /api/keys` → `200`, returns full API key list unauthenticated 4. Cleanup (authenticated): `PATCH /api/settings` body `{"requireLogin":true}` → `GET /api/keys` returns `401` again ### Impact Post-authentication mass assignment. Any authenticated user (including one using the default password) can disable authentication globally, then read all stored API keys and provider connection data without credentials, and toggle tunnel/dashboard exposure. Escalates to remote full compromise when chained with the default password `123456` on an instance exposed via tunnel (`tunnelDashboardAccess` defaults to `true`). ### Suggested fix Whitelist user-configurable fields in the PATCH handler; move security-critical fields (`requireLogin`, `tunnelDashboardAccess`, `authMode`) to a dedicated endpoint requiring re-authentication (current-password re-entry), mirroring the existing DB export/import re-auth flow.

Source published

23 Sep 2026 18:12:33 UTC

Source modified

23 Sep 2026 18:27:57 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

Publisher rating · HIGH