Fluid Attacks Database

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.

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Package	Affected version	Patched versions
debian 11	pypy3	>=0 <7.3.5+dfsg-2	7.3.5+dfsg-2
debian 12	pypy3	>=0 <7.3.5+dfsg-2	7.3.5+dfsg-2
debian 13	pypy3	>=0 <7.3.5+dfsg-2	7.3.5+dfsg-2
debian 14	pypy3	>=0 <7.3.5+dfsg-2	7.3.5+dfsg-2
debian 11	python2.7	=2.7.18-10 \|\| =2.7.18-11 \|\| =2.7.18-12 \|\| =2.7.18-13 \|\| =2.7.18-13.1 \|\| =2.7.18-13.1~exp1 \|\| =2.7.18-13.2 \|\| =2.7.18-8 \|\| =2.7.18-8+deb11u1 \|\| =2.7.18-9	-
debian 11	python3.9	=3.9.2-1 \|\| =3.9.2-1+deb11u1 \|\| >=0 <3.9.2-1+deb11u2	3.9.2-1+deb11u2
rpm rhel6	python	-	-
rpm rhel7	python	-	-
rpm rhel7	python3	-	-
rpm rhel8	python3	<0:3.6.8-45.el8	0:3.6.8-45.el8

Aliases

1. CVE-2021-41892. NVD-2021-41893. OSV-DEBIAN-2021-41894. OSV-2021-41895. SECURITY-TRACKER-CVE-2021-4189

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