CVE-2020-10062Network attack vector

Remote code execution via five-byte MQTT length

Published Jun 5, 2020 · Updated Sep 17, 2024

Integer overflow in Zephyr RTOS 2.2.0 allows remote attackers to corrupt memory and execute code via a malformed MQTT packet. The packet_length_decode function permits a fifth variable-length header byte because it rejects only byte counts greater than four, allowing the length accumulator to overflow. Exploitation requires an application to receive an attacker-controlled MQTT packet, after which corruption occurs in the Zephyr kernel.

CVSS severity9.0
Critical
EPSS probability2.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Zephyr RTOS 2.2.0 allows remote attackers to corrupt memory and execute code via a malformed MQTT packet. The packet_length_decode function permits a fifth variable-length header byte because it rejects only byte counts greater than four, allowing the length accumulator to overflow. Exploitation requires an application to receive an attacker-controlled MQTT packet, after which corruption occurs in the Zephyr kernel.

The record

CVE
CVE-2020-10062
Published
Jun 5, 2020
Updated
Sep 17, 2024
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-193, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 5, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=2.2.0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=2.2.0 <unspecified

Published CVSS scores

9.0Zephyr ProjectCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 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-193Off-by-one Error
T1203Exploitation for Client Execution

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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