Cross Site Scripting Vulnerability on "Import Mail" feature in PHP List

[Songohan22]

Describe the bug
An authenticated malicious user can take advantage of a Stored XSS vulnerability in the "Import Mail" feature.
To Reproduce
Steps to reproduce the behavior:

1. Log into the panel.
2. Go to "/admin/?page=import&tk=6adb3efa27ad1baa355bd3b62671c46b"
3. Click "import by uploading a file with emails"
4. Insert payload:
   <svg/on<script><script>load=alert('XSS')//</script>
5. Click "Save "
6. View the preview to trigger XSS.
7. View the preview to get in request and such Stored XSS

Expected behavior
The removal of script tags is not sufficient to prevent an XSS attack. You must HTML Entity encode any output that is stored back to the page.

Impact
Commonly include transmitting private data, like cookies or other session information, to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user’s machine under the guise of the vulnerable site.

Screenshots

Desktop (please complete the following information):

• OS: Windows
• Browser: Firefox
• Version: 76.0.1

PHP List Version 3.5.5

[Songohan22]

Hi @suap
Please review it! Thanks

[michield]

Resolved with 9c4515c