What’s Vulnerable › Vulnerabilities

CVE-2020-13821

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-08-26 · updated 2026-06-17
• Weakness: CWE-79

Description

An issue was discovered in HiveMQ Broker Control Center 4.3.2. A crafted clientid parameter in an MQTT packet (sent to the Broker) is reflected in the client section of the management console. The attacker's JavaScript is loaded in a browser, which can lead to theft of the session and cookie of the administrator's account of the Broker.

Affected products

• Hivemq Broker Control Center: 4.3.2

References

• https://payatu.com/advisory/hivemq-mqtt-broker---xss-over-mqtt
• https://www.hivemq.com/blog/hivemq-4-3-3-released/
• https://payatu.com/advisory/hivemq-mqtt-broker---xss-over-mqtt
• https://www.hivemq.com/blog/hivemq-4-3-3-released/

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