CVE-2024-31041Public exploitNetwork attack vector

Broker crash via unchecked null topic input

Published Apr 17, 2024 · Updated Aug 22, 2024

Null pointer dereference in NanoMQ 0.21.7 allows remote attackers to crash the MQTT broker by sending crafted packets over TCP. The topic_filtern function passes a null topic-filter pointer as the source argument to strncpy instead of rejecting it before copying into a new buffer. No authentication or user interaction is required; successful delivery aborts the broker process and interrupts MQTT service.

CVSS severity7.5
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Null pointer dereference in NanoMQ 0.21.7 allows remote attackers to crash the MQTT broker by sending crafted packets over TCP. The topic_filtern function passes a null topic-filter pointer as the source argument to strncpy instead of rejecting it before copying into a new buffer. No authentication or user interaction is required; successful delivery aborts the broker process and interrupts MQTT service.

The record

CVE
CVE-2024-31041
Published
Apr 17, 2024
Updated
Aug 22, 2024
Vendor
EMQ Technologies
Product
NanoMQ
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.21.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EMQ Technologies · NanoMQversion=0.21.7

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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