Remove hardcoded internal IP from production hosts allowlist

192.168.2.246 was redundant with the 192.168.0.0/16 regex already in the
CLINCH_ALLOW_INTERNAL_IPS block, and baked a specific lab IP into the repo.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dkam

SECURITY_REVIEW_TODO.md

@@ -0,0 +1,110 @@
+# Security Review — Tracking
+
+Status of findings from the multi-surface security review (OIDC/OAuth2, ForwardAuth,
+WebAuthn/TOTP, sessions, admin/config). Work landed on branch
+`security/forward-auth-and-consent-csrf`.
+
+## ✅ Done (branch `security/forward-auth-and-consent-csrf`)
+
+All HIGH findings are closed. Each fix has tests; suite is green.
+
+| Commit | Fix | Sev |
+|--------|-----|-----|
+| `703d24e` | ForwardAuth fail-open when no host header; consent endpoint CSRF | HIGH ×2 |
+| `8a095e4` | Bearer API-key skipped group check at use-time | HIGH |
+| `96a657e` | Open redirect via unvalidated `X-Forwarded-Host` in login redirect | HIGH |
+| `84ed462` | `CLINCH_HOST` made mandatory in deployed envs; dropped request-host fallback | MEDIUM |
+| `f38ac2e` | TOTP code replay within drift window (+ latent plaintext backup-code bug) | HIGH |
+| `406a79d` | SSRF via `backchannel_logout_uri` (metadata/loopback/RFC1918) | HIGH |
+| `57d7d1f` | Host-auth regex unanchored (`evil-example.com` matched) | HIGH |
+| `89bd5f1` | Disabled user could complete 2FA mid-flow / keep session; enforce active status | HIGH |
+| `cd862c7` | TOTP/backup/OAuth/PKCE `code` params not filtered from logs | MEDIUM |
+| `2426687` | `revoke_family!` didn't revoke access tokens on refresh-token reuse | HIGH |
+| `44892e3` | WebAuthn clone detection logged but didn't block; false-positive on synced passkeys | HIGH |
+| `d49e7ce` | CSP `unsafe-inline` removed (script-src + style-src → nonces) | HIGH |
+
+**Verified false positive (no change):** PKCE *is* required by default —
+`require_pkce` column defaults to `true` (`db/schema.rb`), token endpoint enforces
+it, admin UI exposes the opt-out. Operational check: confirm no legacy confidential
+apps sit on `require_pkce = false`.
+
+**Follow-up before relying on CSP change:** do one manual browser pass (DevTools
+console) on `/signin`, OAuth consent, a Turbo navigation, dark-mode toggle, and a
+WebAuthn sign-in — expect zero CSP violations. Dev is report-only so violations
+surface as warnings without breaking. Fallback if style-src surprises: keep
+`style-src 'unsafe-inline'`, ship script-src only.
+
+## ☐ Remaining — MEDIUM
+
+- [ ] **`id_token_hint` ignored at OIDC logout** — any client can redirect logout to
+      any other registered client's post-logout URI. Validate the hint's `aud` and
+      scope the redirect to that app. `app/controllers/oidc_controller.rb` (logout).
+- [ ] **`offline_access` doesn't gate refresh-token issuance** — refresh tokens are
+      minted unconditionally; gate on the granted scope.
+      `app/controllers/oidc_controller.rb` (authorization_code grant, ~line 564).
+- [ ] **CSP-report endpoint hardening** — unauthenticated, no rate limit / body-size
+      cap, logs raw CRLF (log injection). Sanitize values, cap size, rate-limit.
+      `app/controllers/api/csp_controller.rb`.
+- [ ] **Port not stripped from `X-Forwarded-Host`** in main verify + bearer paths →
+      403 outages on non-standard ports (also a correctness bug). Reuse the
+      port-stripping done in `check_forward_auth_token`.
+      `app/controllers/api/forward_auth_controller.rb`.
+- [ ] **WebAuthn `acr:"2"` without enforced user verification** — `user_verification:
+      "preferred"` lets a PIN-less key authenticate yet reports verified 2FA. Use
+      `"required"`, or downgrade `acr` to `"1"` when the UV flag is absent.
+      `app/controllers/sessions_controller.rb` (webauthn_challenge/verify),
+      `app/controllers/webauthn_controller.rb`.
+- [ ] **`RESERVED_CLAIMS` incomplete** — missing `at_hash`/`auth_time`/`acr`; and
+      `ApplicationUserClaims` has no reserved-name validation (User/Group do). Could
+      let a custom claim overwrite a security claim. `app/services/oidc_jwt_service.rb`,
+      `app/models/application_user_claim.rb`.
+- [ ] **`reset_session` not called on login** — defensive best practice for an IdP;
+      clears pre-auth session state. `app/controllers/concerns/authentication.rb`
+      (`start_new_session_for`).
+- [x] **Hardcoded private IP `192.168.2.246`** in `config/environments/production.rb`
+      — removed; it was redundant with the `192.168.0.0/16` regex already in the
+      `CLINCH_ALLOW_INTERNAL_IPS` block.
+- [ ] **CSP `form-action` widened by unvalidated `redirect_uri`** before auth — only
+      add to `form-action` if the client_id+redirect_uri is a registered pair.
+      `app/controllers/concerns/authentication.rb` (`allow_oauth_redirect_in_csp`).
+- [ ] **SVG `style` attribute permits `url()`/`expression()`** — mitigated today by
+      `Content-Disposition: attachment`, but fragile. Sanitize CSS values or drop
+      `style` from the allowlist. `app/models/svg_scrubber.rb`.
+- [ ] **WebAuthn error messages leak internals** — return generic errors to client,
+      log detail server-side. `app/controllers/sessions_controller.rb`,
+      `app/controllers/webauthn_controller.rb`.
+- [ ] **Account enumeration via webauthn challenge** — distinguishes "user not found"
+      vs "no passkey". Return a uniform message. `app/controllers/sessions_controller.rb`
+      (`webauthn_challenge`).
+- [ ] **`token_family_id` only 31 bits** (`SecureRandom.random_number(2**31)`) —
+      birthday collision ~46k; use a UUID/string. `app/models/oidc_refresh_token.rb`.
+- [ ] **Session cookie uses sequential integer DB id** — HMAC-signed so not forgeable,
+      but consider a random `token` column (Rails 8 generator default).
+      `app/models/session.rb`, `app/controllers/concerns/authentication.rb`.
+- [ ] **Login rate-limit is IP-only** — no account lockout (distributed brute force /
+      credential stuffing). Add failed-count + `locked_until` on users.
+- [ ] **Backup-code rate limit not reset on success** and is cache-based (resets on
+      cache flush). Reset on success; consider DB-backed counter. `app/models/user.rb`.
+
+## ☐ Remaining — LOW / INFO
+
+- [ ] Public clients can't revoke their own tokens (revoke endpoint requires secret).
+- [ ] Basic-auth client creds not URL-decoded per RFC 6749 §2.3.1.
+- [ ] `token_hmac` columns nullable at DB level despite model `presence: true`.
+- [ ] Group names allow commas → injection into `X-Remote-Groups` (false memberships
+      downstream). Add a format validator. `app/models/group.rb`.
+- [ ] `fa_token` leaks in redirect URL / Referer / history (60s TTL, host-bound).
+- [ ] Admin `domain_pattern` allows ReDoS — add a format validator.
+      `app/models/application.rb`.
+- [ ] Forced-TOTP-setup login path can redirect-loop (`totp_required` + no TOTP).
+- [ ] `complete_setup` creates an unprompted session for any authenticated user.
+- [ ] Password min length only 8 — consider 12 + a max (bcrypt 72-byte truncation).
+- [ ] `support_unencrypted_data: true` left enabled (TOTP secret encryption migration).
+      `config/initializers/active_record_encryption.rb`.
+- [ ] All crypto keys derived from a single `SECRET_KEY_BASE` root — document setting
+      independent `ACTIVE_RECORD_ENCRYPTION_*` keys in production.
+- [ ] Log injection via user `email_address` in ForwardAuth logs (strip CRLF / use
+      structured logging). `app/controllers/api/forward_auth_controller.rb`.
+- [ ] WebAuthn RP ID is the registrable domain (cross-subdomain credential roaming) —
+      set `CLINCH_RP_ID` to the exact host unless roaming is intended.
+      `config/initializers/webauthn.rb`.

config/environments/production.rb

@@ -139,9 +139,6 @@ def self.ensure_https(url)
 
   # Allow internal IP access for cross-compose or host networking
   if ENV["CLINCH_ALLOW_INTERNAL_IPS"] == "true"
-    # Specific host IP
-    allowed_hosts << "192.168.2.246"
-
     # Private IP ranges for internal network access
     allowed_hosts += [
       /192\.168\.\d+\.\d+/,    # 192.168.0.0/16 private network