Detections
Analytics

Azure Linux 3.0 Security Update: CBL-Mariner Releases (CVE-2025-66471)

high Nessus Plugin ID 295011

Synopsis

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

Description

The version of CBL-Mariner Releases 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-2025-66471 advisory.

 - urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. When streaming a compressed response, urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd).
 The library must read compressed data from the network and decompress it until the requested chunk size is met. Any resulting decompressed data that exceeds the requested amount is held in an internal buffer for the next read operation. The decompression logic could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This can result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data. (CVE-2025-66471)

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.

Plugin Details

Severity: High

ID: 295011

File Name: azure_linux_CVE-2025-66471.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: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2025-66471

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

CVSS v4

Risk Factor: High

Base Score: 8.9

Threat Score: 6.3

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

CPE: x-cpe:/o:microsoft:azure_linux, p-cpe:/a:microsoft:azure_linux:python-urllib3

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: 12/9/2025

Vulnerability Publication Date: 12/5/2025

Reference Information

CVE: CVE-2025-66471