CVE-2021-4189 - CVE House
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Status published Unknown CVE-2021-4189

A flaw was found in Python, specifically in the FTP...

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

python
Vulnerable Versions:
Fixed in python 3.6.14, python 3.7.11, python 3.8.9, python 3.9.3, python 3.10.0

Timeline

Official Publish: August 24th, 2022
Last Modified: December 17th, 2025
Added to House: July 21st, 2026

CVSS Vectors

No vector data available

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.