CVE-2023-51781

Kernel code execution via unlocked AppleTalk queue access

Published Dec 25, 2023 · Updated Aug 2, 2024

Use-after-free in the Linux kernel before 6.6.8 allows local users to crash the system or execute arbitrary code through AppleTalk. atalk_ioctl reads an skb from sk_receive_queue without holding the queue lock, while atalk_recvmsg can concurrently dequeue and free the same skb. An unprivileged local user can reach the race when the AppleTalk module is available; successful exploitation can corrupt kernel memory.

CVSS severity7.0
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in the Linux kernel before 6.6.8 allows local users to crash the system or execute arbitrary code through AppleTalk. atalk_ioctl reads an skb from sk_receive_queue without holding the queue lock, while atalk_recvmsg can concurrently dequeue and free the same skb. An unprivileged local user can reach the race when the AppleTalk module is available; successful exploitation can corrupt kernel memory.

The record

CVE
CVE-2023-51781
Published
Dec 25, 2023
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.0GitHub Advisory DatabaseCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo