Kimai before 2.65.0 fails to properly validate permissions when removing team access to activities, projects, and customers via API endpoints. Authenticated users with edit_team permission can revoke team access without the required permissions_activity check, bypassing authorization controls.

Kimai before 2.63.0 contains an improper authorization vulnerability in team access endpoints that allows authenticated users with team edit permissions and read-only access to grant team access to customers, projects, or activities. Attackers can exploit insufficient permission checks by sending POST requests to team access endpoints to modify access control lists for entities they should not be able to modify.

Kimai (kimai/kimai) through 2.65.0 contains a business logic / improper authorization vulnerability in the default team creation endpoints. An authenticated user with project permission-management privileges can create or use a customer, project, or activity whose name matches an existing team; because the endpoints POST /api/customers/{id}/team, POST /api/projects/{id}/team, and POST /api/activities/{id}/team reuse an existing team of the same name and add the current user as teamlead without verifying that the user is authorized to manage that team, the attacker gains unauthorized team-lead (administration) rights over the existing team. Fixed in 2.65.0.

Kimai versions before 2.65.0 contain an authorization bypass vulnerability in the REST API timesheet collection endpoint that fails to enforce activity-team access controls. Users with view_other_timesheet permission can list timesheets using activities restricted to teams they do not belong to, bypassing intended data isolation.

Kimai is an open-source time tracking application. In versions 2.52.0 and below, the User Preferences API endpoint (PATCH /api/users/{id}/preferences) applies submitted preference values without checking the isEnabled() flag on preference objects. Although the hourly_rate and internal_rate fields are correctly marked as disabled for users lacking the hourly-rate role permission, the API ignores this restriction and saves the values directly. Any authenticated user can modify their own billing rates through this endpoint, resulting in unauthorized financial tampering affecting invoices and timesheet calculations. This issue has been fixed in version 2.53.0.

Kimai is an open-source time tracking application. In versions 1.16.3 through 2.52.0, the escapeForHtml() function in KimaiEscape.js does not escape double quote or single quote characters. When a user's profile alias is inserted into an HTML attribute context via the team member form prototype and rendered through innerHTML, this incomplete escaping allows HTML attribute injection. An authenticated user with ROLE_USER privileges can store a malicious alias that executes JavaScript in the browser of any administrator viewing the team form, resulting in stored XSS with privilege escalation. This issue has been fixed in version 2.53.0.

Kimai is a web-based multi-user time-tracking application. Prior to version 2.51.0, "GET /api/invoices/{id}" only checks the role-based view_invoice permission but does not verify the requesting user has access to the invoice's customer. Any user with ROLE_TEAMLEAD (which grants view_invoice) can read all invoices in the system, including those belonging to customers assigned to other teams. This issue has been patched in version 2.51.0.

Kimai is a web-based multi-user time-tracking application. Prior to version 2.46.0, Kimai's export functionality uses a Twig sandbox with an overly permissive security policy (`DefaultPolicy`) that allows arbitrary method calls on objects available in the template context. An authenticated user with export permissions can deploy a malicious Twig template that extracts sensitive information including environment variables, all user password hashes, serialized session tokens, and CSRF tokens. Version 2.46.0 patches this issue.