GHSA-qrfh-cc86-vc8c: 
PHP vulnerability analysis and mitigation

Summary

Leantime v2.3.27 is vulnerable to Stored HTML Injection. The firstname and lastname fields in the admin user edit page are rendered without HTML escaping, allowing an authenticated user to inject arbitrary HTML that executes when the profile is viewed.

Vulnerable File

app/Domain/Users/Templates/editUser.tpl.php

Vulnerable Code (Lines ~14-17)

value="<?php echo $values['firstname'] ?>"
value="<?php echo $values['lastname'] ?>"

These fields output raw user input without sanitization.

Steps to Reproduce

1. Login as admin > Go to Settings > Users > Edit any user
2. Enter HTML payload in First Name or Last Name field: <h1>INJECTED</h1>
3. Save the user profile
4. Create or view an article — the injected HTML renders in the author name

Fix

Replace unescaped echo with htmlspecialchars():

value="<?php echo htmlspecialchars($values['firstname'], ENT_QUOTES, 'UTF-8') ?>"
value="<?php echo htmlspecialchars($values['lastname'], ENT_QUOTES, 'UTF-8') ?>"

Or use the existing $this->e() helper already used in editOwn.tpl.php.

Impact

• Stored HTML injection visible to all users viewing affected content
• Can be used for phishing, fake login forms, and UI defacement
• Affects all versions before 3.3.0