Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-002885)

high Nessus Plugin ID 284878

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-2026-002885 advisory.

The Linux Kernel versions 2.6.38 through 4.14 have a problematic use of pmd_mkdirty() in the touch_pmd() function inside the THP implementation. touch_pmd() can be reached by get_user_pages(). In such case, the pmd will become dirty. This scenario breaks the new can_follow_write_pmd()'s logic - pmd can become dirty without going through a COW cycle. This bug is not as severe as the original Dirty cow because an ext4 file (or any other regular file) cannot be mapped using THP. Nevertheless, it does allow us to overwrite read-only huge pages. For example, the zero huge page and sealed shmem files can be overwritten (since their mapping can be populated using THP). Note that after the first write page-fault to the zero page, it will be replaced with a new fresh (and zeroed) thp.

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: 284878

File Name: unity_linux_UTSA-2026-002885.nasl

Version: 1.2

Type: local

Family: Unity Linux Local Security Checks

Published: 1/15/2026

Updated: 1/16/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 8.9

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 6

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

CVSS Score Source: CVE-2017-1000405

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.7

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:H/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: 1/15/2026

Vulnerability Publication Date: 11/30/2017

Reference Information

CVE: CVE-2017-1000405

Detections

Analytics