CVE-2020-13821 json
An issue was discovered in HiveMQ Broker Control Center 4.3.2.
published 2020-08-26 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-6036
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 45%
- public exploits
- 0
- none known
Summary
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.
Exploit prediction
0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
hivemq.com
/blog/hivemq-4-3-3-released/
release-notes, vendor-advisory
-
payatu.com
/advisory/hivemq-mqtt-broker---xss-over-mqtt
third-party-advisory
Sources
- CVE List CVE-2020-13821
- NVD CVE-2020-13821
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.