CVE-2021-4189
5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
0.002 Low
EPSS
Percentile
55.7%
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 configurations
References
access.redhat.com/security/cve/CVE-2021-4189
bugs.python.org/issue43285
bugzilla.redhat.com/show_bug.cgi?id=2036020
github.com/python/cpython/commit/0ab152c6b5d95caa2dc1a30fa96e10258b5f188e
lists.debian.org/debian-lts-announce/2023/05/msg00024.html
lists.debian.org/debian-lts-announce/2023/06/msg00039.html
python-security.readthedocs.io/vuln/ftplib-pasv.html
security-tracker.debian.org/tracker/CVE-2021-4189
security.netapp.com/advisory/ntap-20221104-0004/
Related
5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
0.002 Low
EPSS
Percentile
55.7%