CVE-2019-5432 — A specifically malformed MQTT Subscribe packet crashes MQTT Brokers using the mq

A specifically malformed MQTT Subscribe packet crashes MQTT Brokers using the mqtt-packet module versions < 3.5.1, 4.0.0 - 4.1.3, 5.0.0 - 5.6.1, 6.0.0 - 6.1.2 for decoding.

01What is this vulnerability?

A specifically malformed MQTT Subscribe packet crashes MQTT Brokers using the mqtt-packet module versions < 3.5.1, 4.0.0 - 4.1.3, 5.0.0 - 5.6.1, 6.0.0 - 6.1.2 for decoding.

02Affected products

Vendor	Product	Versions
n	a / mqtt	packet — Vulnerable versions: < 3.5.1, 4.0.0 - 4.1.3, 5.0.0 - 5.6.1, 6.0.0 - 6.1.2

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-05-06T16:48:23.000Z
• Last modified: 2024-08-04T19:54:53.491Z

09References

• hackerone.com — https://hackerone.com/reports/541354