#VU26108 Resource exhaustion in urllib3 - CVE-2020-7212

Vulnerability identifier: #VU26108

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-7212

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
urllib3
Web applications / Modules and components for CMS

Vendor: urlib3

Description

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

The vulnerability exists due to an inefficient algorithm in the "_encode_invalid_chars" function in "util/url.py". A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

urllib3: 1.25.2 - 1.25.7

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External links
https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a
https://pypi.org/project/urllib3/1.25.8/

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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.