CVE-2023-53020

Medium

In the Linux kernel, the following vulnerability has been resolved: l2tp: close all race conditions in l2tp_tunnel_register() The code in l2tp_tunnel_register() is racy in several ways: 1. It modifies the tunnel socket _after_ publishing it. 2. It calls setup_udp_tunnel_sock() on an existing socket without locking. 3. It changes sock lock class on fly, which triggers many syzbot reports. This patch amends all of them by moving socket initialization code before publishing and under sock lock. As suggested by Jakub, the l2tp lockdep class is not necessary as we can just switch to bh_lock_sock_nested().

Package Linux Kernel
Published 2025-03-27
Last modified 2025-10-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

4.7

out of 10
Medium
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-362

CVE-2023-53020 is a Race Condition vulnerability

What is Race Condition?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE

Affected versions

Linux kernel versions 3.6 and later are affected. Fixed in 5.10.166, 5.15.91, 6.1.9, 6.2 and their respective stable series.

Affected from
≥ 3.6
Fixed in
✓ 5.10.166 5.10.x ✓ 5.15.91 5.15.x ✓ 6.1.9 6.1.x ✓ 6.2

References

The following references provide additional information about CVE-2023-53020 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

4 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2023-53020?

    CVE-2023-53020 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 3.6 onward and has been patched in 5.10.166, 5.15.91, 6.1.9 and others. CVE-2023-53020 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2023-53020?

    CVE-2023-53020 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2023-53020?

    Yes — CVE-2023-53020 has been patched. Fixed versions include 5.10.166, 5.15.91, 6.1.9 and others. If you are running Linux kernel 3.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2023-53020 actively exploited?

    No — CVE-2023-53020 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Race Condition (CWE-362)?

    The product contains a code sequence that can run concurrently with other code, creating unexpected states. View CWE-362 on MITRE CWE →

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