Vulnerability identifier: #VU58295

Vulnerability risk: Low

CVSSv3.1: 2.7 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3733

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Python
Universal components / Libraries / Scripting languages

Vendor: Python.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources within the application within the AbstractBasicAuthHandler class in urllib. A remote attacker with control over the server can perform regular expression denial of service attack during authentication.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Python: 3.9.0 - 3.9.4, 3.8 - 3.8.9, 3.7 - 3.7.10, 3.6 - 3.6.13

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External links
http://bugzilla.redhat.com/show_bug.cgi?id=1995234

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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.