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Unity Linux 20.1070e Security Update: pam (UTSA-2026-099450)

high Nessus Plugin ID 336471

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-2026-099450 advisory.

 Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network- adjacent attacker able to repeatedly drive authentication through a calling service to recover the plaintext password of a target account by measuring response-timing differences. The comparison uses strncmp() (or strncasecmp() when PAM_ICASE_ARG is set) preceded by a length-equality check, so the time to reject a candidate depends on the index of the first differing byte and on whether the candidate's length matches the stored password, leaking the password length and individual prefix bytes. The vulnerable path is reached when the administrator configures pam_userdb with crypt=none, with an unrecognized crypt method, or without a crypt= argument, causing the module to store and compare credentials in plaintext.

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 pam package.

See Also

https://atomgit.com/src-openeuler/pam/issues/70

https://nvd.nist.gov/vuln/detail/CVE-2026-54411

http://www.nessus.org/u?a78d01b7

Plugin Details

Severity: High

ID: 336471

File Name: unity_linux_UTSA-2026-099450.nasl

Version: 1.1

Type: Local

Published: 8/17/2026

Updated: 8/17/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.75

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4

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

CVSS Score Source: CVE-2026-54411

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

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

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

CVSS v4

Risk Factor: High

Base Score: 8.2

Threat Score: 4.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/10/2026

Vulnerability Publication Date: 6/14/2026

Reference Information

CVE: CVE-2026-54411