CVE-2021-4189Unchecked Return Value in Python

Severity
5.3MEDIUMNVD
OSV7.6OSV5.7
EPSS
1.1%
top 22.36%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedAug 24
Latest updateJul 11

Description

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NExploitability: 3.9 | Impact: 1.4

Affected Packages2 packages

NVDpython/python3.6.03.6.14+4
CVEListV5python/pythonFixed in python 3.6.14, python 3.7.11, python 3.8.9, python 3.9.3, python 3.10.0

Also affects: Debian Linux 10.0, 11.0, Enterprise Linux 8.0

Patches

🔴Vulnerability Details

7
OSV
python3.5, python3.6, python3.7, python3.8, python3.9, python3.10, python3.11, python3.12 vulnerabilities2024-07-11
GHSA
GHSA-67xf-xphq-9mcc: A flaw was found in Python, specifically in the FTP (File Transfer Protocol) client library in PASV (passive) mode2022-08-25
CVEList
CVE-2021-4189: A flaw was found in Python, specifically in the FTP (File Transfer Protocol) client library in PASV (passive) mode2022-08-24
OSV
CVE-2021-4189: A flaw was found in Python, specifically in the FTP (File Transfer Protocol) client library in PASV (passive) mode2022-08-24
OSV
python2.7 vulnerabilities2022-08-24

📋Vendor Advisories

7
Ubuntu
Python vulnerabilities2024-07-11
CISA ICS
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.12023-12-14
Ubuntu
Python vulnerabilities2022-08-24
Ubuntu
Python vulnerability2022-05-23
Ubuntu
Python vulnerabilities2022-03-28
CVE-2021-4189 — Unchecked Return Value in Python | cvebase