CVE-2021-4189

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.

References

https://security.netapp.com/advisory/ntap-20221104-0004/

https://security-tracker.debian.org/tracker/CVE-2021-4189

https://python-security.readthedocs.io/vuln/ftplib-pasv.html

https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html

https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html

https://github.com/python/cpython/commit/0ab152c6b5d95caa2dc1a30fa96e10258b5f188e

https://bugzilla.redhat.com/show_bug.cgi?id=2036020

https://bugs.python.org/issue43285

https://access.redhat.com/security/cve/CVE-2021-4189

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3