CVE-2020-13599

Security-key disclosure via unrestricted MCUmgr file reads

Published May 24, 2021 · Updated Sep 17, 2024

Information disclosure in Zephyr RTOS 1.14.2 and 2.3.0 allows local users to extract security settings through MCUmgr file management. When the settings subsystem uses LittleFS, it stores secrets such as Bluetooth Mesh device, network, and application keys unencrypted, while MCUmgr file management permits clients to copy files from the device. Exploitation requires the nondefault LittleFS settings and MCUmgr file-management combination plus access to an enabled management transport, and exposes stored secrets without altering or interrupting the device.

CVSS severity3.3
Low
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Zephyr RTOS 1.14.2 and 2.3.0 allows local users to extract security settings through MCUmgr file management. When the settings subsystem uses LittleFS, it stores secrets such as Bluetooth Mesh device, network, and application keys unencrypted, while MCUmgr file management permits clients to copy files from the device. Exploitation requires the nondefault LittleFS settings and MCUmgr file-management combination plus access to an enabled management transport, and exposes stored secrets without altering or interrupting the device.

The record

CVE
CVE-2020-13599
Published
May 24, 2021
Updated
Sep 17, 2024
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-276, CAPEC-1, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 24, 2021CVE 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=1.14.2 <unspecified
  2. Affected versionversion=2.3.0 <unspecified

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=1.14.2 <unspecified; version=2.3.0 <unspecified

Published CVSS scores

3.3GitHub Security AdvisoryCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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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