Leantime: Any Authenticated User Can Self-Escalate to Admin via Unauthorized JSON-RPC Methods (CVE-2026-85990)

### Summary Any authenticated Leantime user - including the lowest-privilege `readonly` role - can escalate to full administrative access by calling the JSON-RPC method `leantime.rpc.api.api.createApiKeyWithProjects` with an attacker-chosen `role` value. The server creates a new account at that role with no authorization check, and the resulting credentials work as a fully interactive admin login through the ordinary web UI. The same root cause (missing per-method authorization on JSON-RPC-exposed service methods) also leaves the `Plugins` service's `installPlugin`, `enablePlugin`, `disablePlugin`, and `removePlugin` methods callable by any authenticated user with no role check, even though their web-UI equivalents correctly require an admin/owner role. ### Details Leantime's JSON-RPC API (`app/Domain/Api/Controllers/Jsonrpc.php`) reflects any public method on any `@api`-annotated service class and dispatches it at `leantime.rpc.{domain}.{service}.{method}`. Per-method authorization is enforced by `PermissionEnforcer::enforce()` (`app/Core/Auth/Permissions/PermissionEnforcer.php`), which reads a `#[RequiresPermission(...)]` PHP attribute off the target method - but when that attribute is **absent**, `enforce()` silently returns and allows the call through. `Api::createApiKeyWithProjects(array $values, ?array $projects)` (`app/Domain/Api/Services/Api.php`) is `@api`-exposed and carries no `#[RequiresPermission]` attribute. It forwards `$values` - including a caller-supplied `role` - directly into `createAPIKey()` → `Users\Repositories\Users::addUser()`, with no server-side clamping of `role` against the calling user's own privilege level: ```php // app/Domain/Api/Services/Api.php /** * @api */ public function createApiKeyWithProjects(array $values, ?array $projects): array|false { $apiKeyValues = $this->createAPIKey($values); // no #[RequiresPermission], no role check ... } ``` The equivalent web route (`NewApiKey` controller) correctly gates account creation behind an admin-only role check (`Auth::authOrRedirect([Roles::$admin, ...])`), but that gate is bypassed entirely by calling the service directly through JSON-RPC. Separately, `Plugins::installPlugin()`, `enablePlugin()`, `disablePlugin()`, and `removePlugin()` (`app/Domain/Plugins/Services/Plugins.php`, lines ~266/299/320/342) share the same gap: all four are `@api`-exposed with no `#[RequiresPermission]`, while their web-controller equivalents (`Myapps.php`, `Details.php`) correctly require `Roles::$owner`/`Roles::$admin`. Authenticating to the JSON-RPC endpoint with an ordinary browser session cookie (rather than a dedicated API key) is sufficient, provided the request carries an `X-Requested-With: XMLHttpRequest` header (`app/Core/Middleware/StartSession.php`) - this is exactly what the application's own first-party JS client already sends, so no special tooling beyond a normal authenticated session is needed. ### PoC A runnable Python PoC (`requests` library only) reproduces this end-to-end; see the attached `poc.py`. Steps: 1. Create/authenticate as a `readonly`-role account (the lowest privilege level). Confirm it is correctly blocked (HTTP 403) from an admin-only page, e.g. `/plugins/myapps`. 2. From that same low-privilege session, send: ``` POST /api/jsonrpc Content-Type: application/json X-Requested-With: XMLHttpRequest {"jsonrpc":"2.0","id":1,"method":"leantime.rpc.api.api.createApiKeyWithProjects", "params":{"values":{"firstname":"poc","role":40,"status":"a"},"projects":[]}} ``` The server responds `HTTP 200` with the newly created account's `user`/`passwordClean` and `"role":40` (admin) in the JSON body. 3. Log in through the normal `/auth/login` form using the returned `user`/`passwordClean`. The resulting session now has full, interactive access to `/plugins/myapps` (HTTP 200) - the exact page that returned 403 in step 1. Reproduced against a local instance built from this repository's own `.dev` Docker tooling (`.dev/docker-compose.yaml`), with dependencies installed via `composer install` / `npx mix` and no modifications to application code. ### Impact Complete compromise of any Leantime instance by an attacker who controls, or can register/be granted, any authenticated account - including the lowest-privilege `readonly` role. No admin credentials, tokens, or prior access beyond an ordinary low-privilege login are required. This is a full authenticated-to-admin privilege escalation (CWE-862 Missing Authorization, CWE-269 Improper Privilege Management). Combined with the plugin-management gap described above, it further extends to arbitrary plugin install/enable/disable/remove, a path toward code-execution-level impact tracked from the same root cause. Script : poc.py ```python #!/usr/bin/env python3 """ What this script does, against a target Leantime instance: 1. Logs in as a LOW-PRIVILEGE account (readonly role by default). 2. Confirms the account is correctly blocked by the n