CentOS Linux 7 [TuxCare] Security Update: python3 / python3-debug / python3-devel / python3-idle / etc Multiple Vulnerabilities (CENTOS7:CLSA-2026:1777970333)

medium Nessus Plugin ID 359950

Synopsis

The CentOS Linux host is missing one or more security updates.

Description

The CentOS Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS7:CLSA-2026:1777970333 advisory.

- The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter. (CVE-2021-23336)

- There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.
(CVE-2021-3733)

- A flaw was found in Python, specifically in the FTP (File Transfer Protocol) client library in PASV (passive) mode. The issue is how the FTP client trusts the host from the PASV response by default. This flaw allows an attacker to set up a malicious FTP server that can trick FTP clients into connecting back to a given IP address and port. This vulnerability could lead to FTP client scanning ports, which otherwise would not have been possible. (CVE-2021-4189)

- The Keccak XKCP SHA-3 reference implementation before fdc6fef has an integer overflow and resultant buffer overflow that allows attackers to execute arbitrary code or eliminate expected cryptographic properties.
This occurs in the sponge function interface. (CVE-2022-37454)

- An issue was discovered in compare_digest in Lib/hmac.py in Python through 3.9.1. Constant-time-defeating optimisations were possible in the accumulator variable in hmac.compare_digest. (CVE-2022-48566)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages based on the guidance in TuxCare advisory CENTOS7:CLSA-2026:1777970333.

Plugin Details

Severity: Medium

ID: 359950

File Name: tuxcare_centos_7_CLSA-2026-1777970333.nasl

Version: 1.1

Type: Local

Agent: unix

Family: CentOS Local Security Checks

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.37

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3.1

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

CVSS Score Source: CVE-2021-23336

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

CVSS Score Source: CVE-2022-37454

CVSS v4

Risk Factor: Medium

Base Score: 6

Threat Score: 5.5

Threat Vector: CVSS:4.0/E:P

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

CVSS Score Source: CVE-2026-1299

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/5/2026

Vulnerability Publication Date: 1/28/2021

Reference Information

CVE: CVE-2021-23336, CVE-2021-3733, CVE-2021-4189, CVE-2022-37454, CVE-2022-48566, CVE-2023-27043, CVE-2026-1299

CLSA: 2026:1777970333

Detections

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