CVE-2023-1252

Local privilege escalation via premature AIO request free

Published Mar 23, 2023 · Updated Apr 23, 2025

Use-after-free in Linux Kernel 5.16-rc1 allows local users to crash the system or escalate privileges through OverlayFS I/O. An asynchronous ext4 direct-I/O completion can free ovl_aio_req and its embedded iocb before vfs_read/write_iter returns, after which file_accessed dereferences the freed iocb. Exploitation requires local low-privileged access, an OverlayFS mount backed by ext4, and concurrent asynchronous file operations; consequences are a kernel crash or privilege escalation.

CVSS severity7.8
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux Kernel 5.16-rc1 allows local users to crash the system or escalate privileges through OverlayFS I/O. An asynchronous ext4 direct-I/O completion can free ovl_aio_req and its embedded iocb before vfs_read/write_iter returns, after which file_accessed dereferences the freed iocb. Exploitation requires local low-privileged access, an OverlayFS mount backed by ext4, and concurrent asynchronous file operations; consequences are a kernel crash or privilege escalation.

The record

CVE
CVE-2023-1252
Published
Mar 23, 2023
Updated
Apr 23, 2025
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=Linux kernel 5.16-rc1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Linux kernel 5.16-rc1

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0OracleCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
5.3SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/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.

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-416Use After Free
T1068Exploitation for Privilege Escalation

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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