PT-2025-13366 · Linux+4 · Linux Kernel+4

Published 2023-05-09 · Updated 2026-01-28 · CVE-2023-53020

Positive Technologies (AI Summary)

CVSS v3.1

4.7

Medium

Base vector

AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability in the Linux kernel has been resolved, specifically in the l2tp tunnel register() function. The issue involved several race conditions, including modifying the tunnel socket after publishing it, calling setup udp tunnel sock() on an existing socket without locking, and changing the sock lock class, which triggered many syzbot reports. The patch addresses these issues by moving socket initialization code before publishing and under the sock lock.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

DoS

Race Condition

Improper Locking

Weakness Enumeration

CWE-362

CWE-667

Related Identifiers

ALSA-2025_16880

BDU:2025-06350

CVE-2023-53020

RHSA-2023:2458

RHSA-2023_2458

SUSE-SU-2025:02334-1

SUSE-SU-2025:02846-1

SUSE-SU-2025:03204-1

SUSE-SU-2025_02334-1

SUSE-SU-2025_02846-1

SUSE-SU-2025_03204-1

SUSE-SU-2026:0316-1

Affected Products

Astra Linux

Linux Kernel

Red Hat

Red Os

Suse

References · 894

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53020.json · Exploit
• https://osv.dev/vulnerability/UBUNTU-CVE-2023-53020 · Vendor Advisory
• https://ubuntu.com/security/CVE-2023-53020 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-06350 · Security Note
• https://osv.dev/vulnerability/CVE-2023-53020 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2025:02334-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2025:03204-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2023-53020 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2023-53020 · Security Note
• https://git.kernel.org/stable/c/0b2c59720e65885a394a017d0cf9cab118914682 · Patch
• https://osv.dev/vulnerability/SUSE-SU-2025:02846-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2026:0316-1 · Vendor Advisory
• https://git.kernel.org/stable/c/2d77e5c0ad79004b5ef901895437e9cce6dfcc7e · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2023-53020 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2023-53020 · Vendor Advisory