ZephyrOperating system · Zephyrproject

CVE-2020-13598

HIGH · 7.8 CVSS v3.1 Published 2021-05-25
Fix available
A fix is available. Upgrade to after 2.3.0 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
FS: Buffer Overflow when enabling Long File Names in FAT_FS and calling fs_stat. Zephyr versions >= v1.14.2, >= v2.3.0 contain Stack-based Buffer Overflow (CWE-121). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-7fhv-rgxr-x56h

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A stack-based buffer overflow vulnerability exists in Zephyr RTOS's FAT_FS implementation. When Long File Names (LFN) are enabled and the fs_stat function is called, the code fails to properly bounds-check buffer allocation, leading to overflow onto the stack. This can potentially allow code execution or denial of service via malformed filesystem stat operations.

MitigationDisable Long File Names (LFN) support in FAT_FS configuration if possible, or upgrade to a patched Zephyr version that properly bounds-checks buffer sizes in the fs_stat function for LFN handling.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ZephyrOperating system
Affected:<= 1.14.2>= 2.0.0, <= 2.3.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Zephyr version in your build
    Locate the version file in your Zephyr installation (such as VERSION file in the top-level Zephyr directory) or check the version reported by the build system
    Affected if The version is 1.14.2 or earlier, or falls between 2.0.0 and 2.3.0 inclusive
  2. Confirm FAT_FS filesystem support is enabled
    Examine your build configuration (defconfig, prj.conf, or .config) for CONFIG_FAT_FILESYSTEMS or similar Kconfig options that enable FAT filesystem support
    Affected if FAT filesystem support is enabled in your configuration
  3. Verify Long File Name (LFN) support is enabled in FAT_FS
    Look in your build configuration for CONFIG_FS_FATFS_LFN or equivalent option that enables Long File Name support in the FAT filesystem driver
    Affected if LFN support is explicitly enabled in your FAT_FS configuration
  4. Confirm usage of fs_stat function
    Review your application source code and verify if the fs_stat() function or equivalent stat operations are being called on FAT filesystem paths
    Affected if Your code calls fs_stat() or related stat functions on FAT filesystem objects

You are affected if your Zephyr version falls within the vulnerable range, FAT_FS with LFN is enabled, and your code invokes fs_stat on FAT filesystem paths.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 2.3.0
Interim mitigation

Disable Long File Names (LFN) support in FAT_FS configuration if possible, or upgrade to a patched Zephyr version that properly bounds-checks buffer sizes in the fs_stat function for LFN handling.

Fix this in Zephyr Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,970
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-13598 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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