RHEL 7 : python27 (RHSA-2021:3252)

high Nessus Plugin ID 152778

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Synopsis

The remote Red Hat host is missing one or more security updates for python27.

Description

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:3252 advisory.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

* python: Unsafe use of eval() on data retrieved via HTTP in the test suite (CVE-2020-27619)

* python-jinja2: ReDoS vulnerability due to the sub-pattern (CVE-2020-28493)

* python: Stack-based buffer overflow in PyCArg_repr in _ctypes/callproc.c (CVE-2021-3177)

* python-babel: Relative path traversal allows attacker to load arbitrary locale files and execute arbitrary code (CVE-2021-20095)

* python-pygments: Infinite loop in SML lexer may lead to DoS (CVE-2021-20270)

* python: Web cache poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a semicolon in query parameters (CVE-2021-23336)

* python-pygments: ReDoS via crafted malicious input (CVE-2021-27291)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional information

* Changes in the default separator for the Python urllib parsing functions

To mitigate the Web Cache Poisoning CVE-2021-23336 in the Python urllib library, the default separator for the urllib.parse.parse_qsl and urllib.parse.parse_qs functions is being changed from both ampersand (&) and semicolon (;) to only an ampersand.

The change of the default separator is potentially backwards incompatible, therefore Red Hat provides a way to configure the behavior in Python packages where the default separator has been changed. In addition, the affected urllib parsing functions issue a warning if they detect that a customers application has been affected by the change.

For more information, see the Knowledgebase article Mitigation of Web Cache Poisoning in the Python urllib library (CVE-2021-23336) linked from the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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 RHEL python27 package based on the guidance in RHSA-2021:3252.

Plugin Details

Severity: High

ID: 152778

File Name: redhat-RHSA-2021-3252.nasl

Version: 1.12

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 8/24/2021

Updated: 9/10/2025

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

CVSS Score Source: CVE-2021-3177

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 v4

Risk Factor: High

Base Score: 8.7

Threat Score: 7.4

Threat Vector: CVSS:4.0/E:P

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

CVSS Score Source: CVE-2021-42771

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:python27-python-jinja2, p-cpe:/a:redhat:enterprise_linux:python27-python-devel, p-cpe:/a:redhat:enterprise_linux:python27-python-libs, p-cpe:/a:redhat:enterprise_linux:python27-python-pygments, p-cpe:/a:redhat:enterprise_linux:python27-tkinter, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:redhat:enterprise_linux:python27-python-babel, p-cpe:/a:redhat:enterprise_linux:python27-python-test, p-cpe:/a:redhat:enterprise_linux:python27-python, p-cpe:/a:redhat:enterprise_linux:python27-python-tools, p-cpe:/a:redhat:enterprise_linux:python27-babel, p-cpe:/a:redhat:enterprise_linux:python27-python-debug

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/24/2021

Vulnerability Publication Date: 10/22/2020

Reference Information

CVE: CVE-2020-27619, CVE-2020-28493, CVE-2021-20270, CVE-2021-23336, CVE-2021-27291, CVE-2021-3177, CVE-2021-42771

CWE: 120, 22, 400, 444, 835, 95

IAVA: 2021-A-0052-S, 2021-A-0263-S

RHSA: 2021:3252

Detections

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