CVE-2021-4189

    Dashboard / Vulnerabilities / CVE-2021-4189

    CVE-2021-4189

    Published: 24 Aug 2022Last Modified: 27 Sept 2026

    Summary:

    Details: 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://lists.debian.org/debian-lts-announce/2023/05/msg00024.html, https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html, https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html, https://access.redhat.com/security/cve/CVE-2021-4189, https://security-tracker.debian.org/tracker/CVE-2021-4189, https://security.netapp.com/advisory/ntap-20221104-0004/, https://bugs.python.org/issue43285, https://bugzilla.redhat.com/show_bug.cgi?id=2036020, https://github.com/python/cpython/commit/0ab152c6b5d95caa2dc1a30fa96e10258b5f188e, https://python-security.readthedocs.io/vuln/ftplib-pasv.html

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 5c4568a05a0a62b5947c55f68f9f2ecfb90a4f12
    Fixed -9a0099d1bf14bce417370aae6d55527417cda354

    Affected versions

    3.10.0-NA

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2021-4189 | CVE-DB