CVE-2023-33658Network attack vector

Service crash via malformed PUBLISH packet parsing

Published Jun 8, 2023 · Updated Jan 6, 2025

Heap buffer overflow in NanoMQ 0.17.2 allows remote attackers to crash the broker by sending a malformed MQTT PUBLISH packet. The affected receive paths call nni_msg_get_pub_pid() without first rejecting an invalid QoS value or a missing packet identifier, allowing malformed message data to drive an out-of-bounds heap access. Anonymous MQTT access is sufficient when a vulnerable listener is reachable; exploitation interrupts broker availability, with no documented confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability1.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in NanoMQ 0.17.2 allows remote attackers to crash the broker by sending a malformed MQTT PUBLISH packet. The affected receive paths call nni_msg_get_pub_pid() without first rejecting an invalid QoS value or a missing packet identifier, allowing malformed message data to drive an out-of-bounds heap access. Anonymous MQTT access is sufficient when a vulnerable listener is reachable; exploitation interrupts broker availability, with no documented confidentiality or integrity impact.

The record

CVE
CVE-2023-33658
Published
Jun 8, 2023
Updated
Jan 6, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA ADP VulnrichmentCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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