cvedb.io
CVE-2021-4189
MEDIUM · CVSS 5.3
EPSS exploitation probability: 0%
Published 2022-08-24T16:15:09.827 · Last modified 2026-06-17T04:19:11.137

Summary

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.

Affected products

python — python

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.