MitM attack in cryptography package for Python

1) Improper certificate validation

EUVDB-ID: #VU79490

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-38325

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to improper certificate validation when handling SSH certificates that have critical options. A remote attacker can perform MitM attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

cryptography: 40.0.0 - 41.0.1

CPE2.3

• cpe:2.3:a:Сryptography:cryptography:40.0.0:*:*:*:*:python:*:*
• cpe:2.3:a:Сryptography:cryptography:40.0.1:*:*:*:*:python:*:*
• cpe:2.3:a:Сryptography:cryptography:40.0.2:*:*:*:*:python:*:*

External links

https://github.com/pyca/cryptography/compare/41.0.1...41.0.2
https://github.com/pyca/cryptography/issues/9207
https://github.com/pyca/cryptography/pull/9208

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.