Unity Linux 20.1070e Security Update: kernel (UTSA-2026-000347)

high Nessus Plugin ID 282021

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-2026-000347 advisory.

In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.

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: High

ID: 282021

File Name: unity_linux_UTSA-2026-000347.nasl

Version: 1.1

Type: local

Family: Unity Linux Local Security Checks

Published: 1/7/2026

Updated: 1/7/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: Medium

Base Score: 4.4

Temporal Score: 3.6

Vector: CVSS2#AV:L/AC:M/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2018-18955

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.5

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

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

Vulnerability Information

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 1/7/2026

Vulnerability Publication Date: 11/16/2018

Reference Information

CVE: CVE-2018-18955

Detections

Analytics