## https://sploitus.com/exploit?id=8F82B686-02AE-51A7-BC8D-1032B4239E8F
---
## CVE-2026-21015 – PHP Filter Chain Arbitrary File Read
### Program Code (PHP)
```php
// vulnerable.php - Includes file based on user input via filter
<?php
$file = $_GET['page'];
// Attempt to sanitize by allowing only .php files, but vulnerable to filter wrapper
include("php://filter/convert.base64-encode/resource=" . $file);
```
# CVE-2026-21015 – PHP Filter Chain Arbitrary File Read

## Overview
A PHP application uses `php://filter` to include files based on user input without proper validation. An attacker can leverage the base64‑encode filter and path traversal to read arbitrary files on the server.
## Vulnerability Details
- **Type:** Local File Inclusion (LFI)
- **Impact:** Source code disclosure, credential theft.
- **Root Cause:** The script prepends the filter wrapper but does not restrict which files can be included; directory traversal is still possible.
## Exploit Demonstration
1. Start a PHP server with the vulnerable script.
2. Run the exploit:
```bash
python exploit_php_filter.py
The content of /etc/passwd is returned.