Detections
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Azure Linux 3.0 Security Update: kernel (CVE-2025-21744)

medium Nessus Plugin ID 295874

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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-2025-21744 advisory.

 - In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: fix NULL pointer dereference in brcmf_txfinalize() On removal of the device or unloading of the kernel module a potential NULL pointer dereference occurs. The following sequence deletes the interface: brcmf_detach() brcmf_remove_interface() brcmf_del_if() Inside the brcmf_del_if() function the drvr->if2bss[ifidx] is updated to BRCMF_BSSIDX_INVALID (-1) if the bsscfgidx matches. After brcmf_remove_interface() call the brcmf_proto_detach() function is called providing the following sequence: brcmf_detach() brcmf_proto_detach() brcmf_proto_msgbuf_detach() brcmf_flowring_detach() brcmf_msgbuf_delete_flowring() brcmf_msgbuf_remove_flowring() brcmf_flowring_delete() brcmf_get_ifp() brcmf_txfinalize() Since brcmf_get_ip() can and actually will return NULL in this case the call to brcmf_txfinalize() will result in a NULL pointer dereference inside brcmf_txfinalize() when trying to update ifp->ndev->stats.tx_errors.
 This will only happen if a flowring still has an skb. Although the NULL pointer dereference has only been seen when trying to update the tx statistic, all other uses of the ifp pointer have been guarded as well with an early return if ifp is NULL. (CVE-2025-21744)

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-2025-21744

Plugin Details

Severity: Medium

ID: 295874

File Name: azure_linux_CVE-2025-21744.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-2025-21744

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

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

Exploit Ease: No known exploits are available

Patch Publication Date: 3/11/2025

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2025-21744