Detections
Analytics

Linux Distros Unpatched Vulnerability : CVE-2021-3733

medium Nessus Plugin ID 224011

Language:

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

 - 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)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2021-3733

https://security-tracker.debian.org/tracker/CVE-2021-3733

Plugin Details

Severity: Medium

ID: 224011

File Name: unpatched_CVE_2021_3733.nasl

Version: 1.2

Type: local

Agent: unix

Family: Misc.

Published: 3/5/2025

Updated: 8/20/2025

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3.1

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

CVSS Score Source: CVE-2021-3733

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.9

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, p-cpe:/a:centos:centos:python36, cpe:/o:centos:centos:8, p-cpe:/a:redhat:enterprise_linux:python36, p-cpe:/a:debian:debian_linux:python2.7, cpe:/o:redhat:enterprise_linux:8

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 9/20/2021

Reference Information

CVE: CVE-2021-3733