CVE-2023-4273Public exploit

Kernel protection bypass via overlong exFAT filenames

Published Aug 9, 2023 · Updated Nov 14, 2025

Stack-based buffer overflow in the exFAT driver in Red Hat Enterprise Linux 9 allows local users to overwrite kernel memory. exfat_get_uniname_from_ext_entry accepts excess filename entries and copies their characters into a 258-character stack array without enforcing the 255-character limit. Administrative privileges and a crafted exFAT filesystem are required; exploitation can disable kernel lockdown, load unsigned modules, or panic the kernel.

CVSS severity6.0
Medium
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in the exFAT driver in Red Hat Enterprise Linux 9 allows local users to overwrite kernel memory. exfat_get_uniname_from_ext_entry accepts excess filename entries and copies their characters into a 258-character stack array without enforcing the 255-character limit. Administrative privileges and a crafted exFAT filesystem are required; exploitation can disable kernel lockdown, load unsigned modules, or panic the kernel.

The record

CVE
CVE-2023-4273
Published
Aug 9, 2023
Updated
Nov 14, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 9
Classifications
CWE-121, CWE-787, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Aug 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 14, 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

6.7NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6.0Red HatCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation

Public exploit references

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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