vulnerability
Red Hat: CVE-2021-4189: ftplib should not use the host from the PASV response (Multiple Advisories)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:P/I:N/A:N) | May 10, 2022 | May 13, 2022 | Mar 27, 2026 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:P/I:N/A:N)
Published
May 10, 2022
Added
May 13, 2022
Modified
Mar 27, 2026
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.
Solutions
redhat-upgrade-babelredhat-upgrade-cython-debugsourceredhat-upgrade-numpy-debugsourceredhat-upgrade-platform-pythonredhat-upgrade-platform-python-debugredhat-upgrade-platform-python-develredhat-upgrade-python-coverage-debugsourceredhat-upgrade-python-lxml-debugsourceredhat-upgrade-python-nose-docsredhat-upgrade-python-psycopg2-debuginforedhat-upgrade-python-psycopg2-debugsourceredhat-upgrade-python-psycopg2-docredhat-upgrade-python-pymongo-debuginforedhat-upgrade-python-pymongo-debugsourceredhat-upgrade-python-sqlalchemy-docredhat-upgrade-python2redhat-upgrade-python2-attrsredhat-upgrade-python2-babelredhat-upgrade-python2-backportsredhat-upgrade-python2-backports-ssl_match_hostnameredhat-upgrade-python2-bsonredhat-upgrade-python2-bson-debuginforedhat-upgrade-python2-chardetredhat-upgrade-python2-coverageredhat-upgrade-python2-coverage-debuginforedhat-upgrade-python2-cythonredhat-upgrade-python2-cython-debuginforedhat-upgrade-python2-debugredhat-upgrade-python2-debuginforedhat-upgrade-python2-debugsourceredhat-upgrade-python2-develredhat-upgrade-python2-dnsredhat-upgrade-python2-docsredhat-upgrade-python2-docs-inforedhat-upgrade-python2-docutilsredhat-upgrade-python2-funcsigsredhat-upgrade-python2-idnaredhat-upgrade-python2-ipaddressredhat-upgrade-python2-jinja2redhat-upgrade-python2-libsredhat-upgrade-python2-lxmlredhat-upgrade-python2-lxml-debuginforedhat-upgrade-python2-markupsaferedhat-upgrade-python2-mockredhat-upgrade-python2-noseredhat-upgrade-python2-numpyredhat-upgrade-python2-numpy-debuginforedhat-upgrade-python2-numpy-docredhat-upgrade-python2-numpy-f2pyredhat-upgrade-python2-pipredhat-upgrade-python2-pip-wheelredhat-upgrade-python2-pluggyredhat-upgrade-python2-psycopg2redhat-upgrade-python2-psycopg2-debugredhat-upgrade-python2-psycopg2-debug-debuginforedhat-upgrade-python2-psycopg2-debuginforedhat-upgrade-python2-psycopg2-testsredhat-upgrade-python2-pyredhat-upgrade-python2-pygmentsredhat-upgrade-python2-pymongoredhat-upgrade-python2-pymongo-debuginforedhat-upgrade-python2-pymongo-gridfsredhat-upgrade-python2-pymysqlredhat-upgrade-python2-pysocksredhat-upgrade-python2-pytestredhat-upgrade-python2-pytest-mockredhat-upgrade-python2-pytzredhat-upgrade-python2-pyyamlredhat-upgrade-python2-pyyaml-debuginforedhat-upgrade-python2-requestsredhat-upgrade-python2-rpm-macrosredhat-upgrade-python2-scipyredhat-upgrade-python2-scipy-debuginforedhat-upgrade-python2-setuptoolsredhat-upgrade-python2-setuptools-wheelredhat-upgrade-python2-setuptools_scmredhat-upgrade-python2-sixredhat-upgrade-python2-sqlalchemyredhat-upgrade-python2-testredhat-upgrade-python2-tkinterredhat-upgrade-python2-toolsredhat-upgrade-python2-urllib3redhat-upgrade-python2-virtualenvredhat-upgrade-python2-wheelredhat-upgrade-python2-wheel-wheelredhat-upgrade-python3-debuginforedhat-upgrade-python3-debugsourceredhat-upgrade-python3-idleredhat-upgrade-python3-libsredhat-upgrade-python3-testredhat-upgrade-python3-tkinterredhat-upgrade-pyyaml-debugsourceredhat-upgrade-scipy-debugsource
Rapid7 Labs
2026 Global Threat Landscape Report
The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.