CVE-2020-13821 Explained : Impact and Mitigation

An issue was discovered in HiveMQ Broker Control Center 4.3.2 where a crafted clientid parameter in an MQTT packet can lead to a reflected XSS vulnerability.

Understanding CVE-2020-13821

What is CVE-2020-13821?

This CVE identifies a vulnerability in HiveMQ Broker Control Center 4.3.2 that allows an attacker to execute a reflected XSS attack by manipulating the clientid parameter in an MQTT packet.

The Impact of CVE-2020-13821

The exploitation of this vulnerability can result in the theft of the session and cookie of the administrator's account of the Broker, potentially compromising sensitive information.

Technical Details of CVE-2020-13821

Vulnerability Description

The issue arises from the improper handling of the clientid parameter in MQTT packets, leading to the execution of malicious JavaScript in the context of the management console.

Affected Systems and Versions

HiveMQ Broker Control Center 4.3.2

Exploitation Mechanism

The attacker sends a specially crafted MQTT packet with a malicious clientid parameter, which, when reflected in the management console, executes the attacker's JavaScript code.

Mitigation and Prevention

Immediate Steps to Take

Update to the latest version of HiveMQ Broker Control Center to patch the vulnerability.
Monitor network traffic for any suspicious MQTT packets.
Implement strict input validation to prevent injection attacks.

Long-Term Security Practices

Regularly audit and review MQTT packet handling mechanisms.
Educate administrators and users about the risks of XSS attacks and how to identify suspicious activity.

Patching and Updates

Apply security patches and updates promptly to ensure the protection of the system against known vulnerabilities.