CVE-2020-10070Network attack vector

Remote code execution via MQTT length overflow

Published Jun 5, 2020 · Updated Sep 16, 2024

Buffer overflow in Zephyr RTOS 2.2.0 allows remote attackers to corrupt memory or execute code via a crafted MQTT packet. mqtt_read_message_chunk subtracts buffered bytes from an attacker-controlled packet length and fails to detect pointer wraparound before reading transport data beyond the receive buffer. The MQTT client must process the packet through its broker connection; exploitation can crash the device or execute code in the firmware context.

CVSS severity9.8
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

Buffer overflow in Zephyr RTOS 2.2.0 allows remote attackers to corrupt memory or execute code via a crafted MQTT packet. mqtt_read_message_chunk subtracts buffered bytes from an attacker-controlled packet length and fails to detect pointer wraparound before reading transport data beyond the receive buffer. The MQTT client must process the packet through its broker connection; exploitation can crash the device or execute code in the firmware context.

The record

CVE
CVE-2020-10070
Published
Jun 5, 2020
Updated
Sep 16, 2024
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-190, CWE-120, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 5, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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

9.8NIST 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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
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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