CVE-2023-4260

Stack corruption via off-by-one FUSE path write

Published Sep 26, 2023 · Updated Feb 13, 2025

Buffer overflow in the FUSE filesystem layer in Zephyr RTOS 3.4.0 and earlier allows local users to corrupt stack memory. The fuse_fs_access_readdir function appends a slash with sprintf to a PATH_MAX-sized path in a PATH_MAX stack buffer, writing the terminating NUL one byte past mount_path. The path must reach a FUSE mount-point directory from a low-privileged local context; the resulting corruption can crash the process or execute code across the security boundary.

CVSS severity6.3
Medium
EPSS probability0.77%
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 the FUSE filesystem layer in Zephyr RTOS 3.4.0 and earlier allows local users to corrupt stack memory. The fuse_fs_access_readdir function appends a slash with sprintf to a PATH_MAX-sized path in a PATH_MAX stack buffer, writing the terminating NUL one byte past mount_path. The path must reach a FUSE mount-point directory from a low-privileged local context; the resulting corruption can crash the process or execute code across the security boundary.

The record

CVE
CVE-2023-4260
Published
Sep 26, 2023
Updated
Feb 13, 2025
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-120, CWE-193
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 26, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=0 <=3.4

Published CVSS scores

10.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
6.3Zephyr Project GitHub Security AdvisoryCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-193Off-by-one Error

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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