Executive brief
OpenReception's appointment booking platform allows clients to securely schedule appointments with end-to-end encryption. Before version 1.0.5, an attacker could forge appointments into any client's tunnel without authentication by supplying any valid tunnel ID and email hash, creating confirmed bookings with attacker-controlled dates, times, and assigned agents. This allows unauthorized access to appointment slots and could be used for appointment fraud or service disruption.
Technical details
The vulnerability is an authentication bypass in the `add-to-tunnel` endpoint, which lacks any caller authentication (no session, Authorization header, or access token). The endpoint accepts a `tunnelId` and `emailHash` supplied by the attacker, validates only that some tunnel exists with the given `emailHash`, and then writes an appointment directly to the attacker-supplied `tunnelId` without verifying ownership. The endpoint is explicitly listed in the public-route allowlist despite being intended for return clients, whereas the analogous `create-new-client` endpoint correctly requires a Bearer bootstrap token. An attacker can craft requests to insert arbitrary appointments with attacker-controlled ciphertext fields, dates, durations, and agent assignments into any tunnel. The fix in version 1.0.5 adds proper authentication checks.
Affected products
- OpenReception Appointment Booking Software before 1.0.5
Timeline
- 2026-08-06: disclosed
- 2026-08-06: patched: Version 1.0.5 fixes the authentication bypass