Summary
Firefly III user API endpoints expose all users' information to any authenticated user (IDOR)
The User management API endpoints (GET /api/v1/users and GET /api/v1/users/{id}) are accessible to any authenticated user without admin/owner role verification, exposing all users' email addresses, roles, and account status.
Affected Endpoints
- GET /api/v1/users (UserController::index, line 94), Lists ALL users with full details. No role check.
- GET /api/v1/users/{id} (UserController::show, line 126), Shows any user's details by ID. No role check.
Root Cause (1-of-N Inconsistency)
Other methods in the same controller properly check for the 'owner' role:
store(),UserStoreRequest::authorize()checksauth()->user()->hasRole('owner')✓destroy(), Explicitly checks$this->repository->hasRole($admin, 'owner')✓
But index() and show() have no role check at all. The route group at routes/api.php:734-747 has no admin middleware, only the global auth:api middleware.
Exposed Data
The UserTransformer (line 40-54) returns:
email, user's email addressrole, user's role (owner/demo)blocked, account blocked statusblocked_code, block reasoncreated_at/updated_at, timestamps
Exploitation
# List all users
curl -H "Authorization: Bearer <any_user_token>" https://instance/api/v1/users
# View specific user details
curl -H "Authorization: Bearer <any_user_token>" https://instance/api/v1/users/1
Impact
Any authenticated user can:
- Enumerate ALL user accounts in the instance
- Harvest email addresses for phishing/social engineering
- Identify admin/owner accounts by role
- Determine which accounts are blocked
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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Add owner role checks to index() and show(), or restrict the route group with admin middleware:
// Option 1: Add check in controller methods
public function show(User $user): JsonResponse
{
if (!$this->repository->hasRole(auth()->user(), 'owner') && auth()->user()->id !== $user->id) {
throw new FireflyException('200025: No access to function.');
}
// ...
}
// Option 2: Add middleware to route group
Route::group(['middleware' => ['admin'], ...], ...)
Frequently Asked Questions
- What is GHSA-5Q8V-J673-M5V4? GHSA-5Q8V-J673-M5V4 is a medium-severity incorrect authorization vulnerability in grumpydictator/firefly-iii (composer), affecting versions >= 6.4.23, <= 6.5.0. It is fixed in 6.5.1. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- Which versions of grumpydictator/firefly-iii are affected by GHSA-5Q8V-J673-M5V4? grumpydictator/firefly-iii (composer) versions >= 6.4.23, <= 6.5.0 is affected.
- Is there a fix for GHSA-5Q8V-J673-M5V4? Yes. GHSA-5Q8V-J673-M5V4 is fixed in 6.5.1. Upgrade to this version or later.
- Is GHSA-5Q8V-J673-M5V4 exploitable, and should I be worried? Whether GHSA-5Q8V-J673-M5V4 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-5Q8V-J673-M5V4 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-5Q8V-J673-M5V4? Upgrade
grumpydictator/firefly-iiito 6.5.1 or later.