Detections
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Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-004322)
medium Nessus Plugin ID 288753
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-2026-004322 advisory.Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if, for example, unprivileged user namespaces were allowed. It was possible to have a file not readable by an unprivileged user to be copied to a mountpoint controlled by the user, like a removable device. This was introduced in kernel version 4.19 by commit d1d04ef (ovl:
stack file ops). This was fixed in kernel version 5.8 by commits 56230d9 (ovl: verify permissions in ovl_path_open()), 48bd024 (ovl: switch to mounter creds in readdir) and 05acefb (ovl: check permission to open real file). Additionally, commits 130fdbc (ovl: pass correct flags for opening real directory) and 292f902 (ovl: call secutiry hook in ovl_real_ioctl()) in kernel 5.8 might also be desired or necessary. These additional commits introduced a regression in overlay mounts within user namespaces which prevented access to files with ownership outside of the user namespace. This regression was mitigated by subsequent commit b6650da (ovl: do not fail because of O_NOATIMEi) in kernel 5.11.
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.See Also
Plugin Details
Severity: Medium
ID: 288753
File Name: unity_linux_UTSA-2026-004322.nasl
Version: 1.2
Type: local
Published: 1/16/2026
Updated: 1/16/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Low
Base Score: 2.1
Temporal Score: 1.6
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N
CVSS Score Source: CVE-2020-16120
CVSS v3
Risk Factor: Medium
Base Score: 4.4
Temporal Score: 3.9
Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
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: 1/16/2026
Vulnerability Publication Date: 10/13/2020
Reference Information
CVE: CVE-2020-16120