#VU58295 Resource management error in Python - CVE-2021-3733

Vulnerability identifier: #VU58295

Vulnerability risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

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: 3.6 - 3.6.13, 3.7 - 3.7.10, 3.8 - 3.8.9, 3.9.0b4 - 3.9.4

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External links
https://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.