Unity Linux 20.1050e Security Update: kernel (UTSA-2026-021642)

medium Nessus Plugin ID 315873

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-021642 advisory.

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().

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

Plugin Details

Severity: Medium

ID: 315873

File Name: unity_linux_UTSA-2026-021642.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 5/20/2026

Updated: 5/20/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Low

Base Score: 3.8

Temporal Score: 2.8

Vector: CVSS2#AV:L/AC:H/Au:S/C:N/I:N/A:C

CVSS Score Source: CVE-2023-53020

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 4.1

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 5/21/2026

Vulnerability Publication Date: 7/21/2021

Reference Information

CVE: CVE-2023-53020

Detections

Analytics