OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, a TENANT_ADMIN can store `javascript:` URLs in the tenant `links` configuration (`website`, `imprint`, `privacyStatement`). These values are returned to the patient-facing landing page via `/api/public`, hydrated into the SvelteKit Button component, and rendered as `<a href="javascript:...">` elements without URL-scheme filtering.
A patient who clicks any such link executes the attacker's JavaScript inside the patient browser origin, where patient form data is read before client-side encryption is applied. This breaks the project's central trust claim that the server is an untrusted relay and that administrators cannot read patient data. Patient-side encryption happens after form input, so JavaScript executing in the patient origin can read or alter the plaintext before encryption is performed.
Version 1.0.2 fixes the issue.
Attack Parameters
Impact Assessment
CVSS Vector v3.1