Python FTP Client Library return value

Summaryinfo

A vulnerability was found in Python. It has been classified as problematic. Affected is an unknown function of the component FTP Client Library. The manipulation leads to an unknown weakness. This vulnerability is uniquely identified as CVE-2021-4189. The attack is possible to be carried out remotely. No exploit exists. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Python (Programming Language Software) (unknown version). It has been rated as problematic. This issue affects an unknown code block of the component FTP Client Library. Using CWE to declare the problem leads to CWE-252. The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was disclosed 08/25/2022 as 0ab152c6b5d95caa2dc1a30fa96e10258b5f188e. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2021-4189 since 12/29/2021. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 211144 (Fedora 37 : python2.7 (2022-b8559307db)), which helps to determine the existence of the flaw in a target environment.

Applying the patch 0ab152c6b5d95caa2dc1a30fa96e10258b5f188e is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the databases at Tenable (211144), EUVD (EUVD-2021-34049) and CERT Bund (WID-SEC-2022-0011). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• F5 F5OS
• Open Source Python
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• Oracle Linux
• Avaya Aura Communication Manager
• Avaya Aura Session Manager
• Avaya Aura Application Enablement Services
• Avaya Aura Device Services
• Avaya Aura System Manager
• Avaya Aura Experience Portal
• IBM QRadar SIEM
• F5 BIG-IP

Productinfo

Type

• Programming Language Software

Name

• Python

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion