Detections
Analytics

Azure Linux 3.0 Security Update: kernel (CVE-2025-21745)

medium Nessus Plugin ID 295736

Synopsis

The remote Azure Linux host is missing one or more security updates.

Description

The version of kernel installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2025-21745 advisory.

 - In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Fix class @block_class's subsystem refcount leakage blkcg_fill_root_iostats() iterates over @block_class's devices by class_dev_iter_(init|next)(), but does not end iterating with class_dev_iter_exit(), so causes the class's subsystem refcount leakage. Fix by ending the iterating with class_dev_iter_exit(). (CVE-2025-21745)

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 packages.

See Also

https://nvd.nist.gov/vuln/detail/CVE-2025-21745

Plugin Details

Severity: Medium

ID: 295736

File Name: azure_linux_CVE-2025-21745.nasl

Version: 1.1

Type: local

Published: 1/22/2026

Updated: 1/22/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2025-21745

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/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

CPE: p-cpe:/a:microsoft:azure_linux:kernel-tools, p-cpe:/a:microsoft:azure_linux:kernel-devel, p-cpe:/a:microsoft:azure_linux:kernel-debuginfo, p-cpe:/a:microsoft:azure_linux:kernel-docs, p-cpe:/a:microsoft:azure_linux:kernel-drivers-intree-amdgpu, p-cpe:/a:microsoft:azure_linux:bpftool, p-cpe:/a:microsoft:azure_linux:python3-perf, p-cpe:/a:microsoft:azure_linux:kernel-drivers-gpu, p-cpe:/a:microsoft:azure_linux:kernel-drivers-sound, p-cpe:/a:microsoft:azure_linux:kernel-drivers-accessibility, x-cpe:/o:microsoft:azure_linux, p-cpe:/a:microsoft:azure_linux:kernel

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

Exploit Ease: No known exploits are available

Patch Publication Date: 3/11/2025

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2025-21745