Vulnerability identifier: #VU50989

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-21240

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
httplib2
Other software / Other software solutions

Vendor: httplib2

Description

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

The vulnerability exists due to application does not properly control consumption of internal resources. A remote attacker can trigger resource exhaustion by tricking the application to connect to a malicious server that responds with long series of "xa0" characters in the "www-authenticate" header.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

httplib2: 0.9 - 0.18.1

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External links
http://github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc
http://github.com/httplib2/httplib2/pull/182
http://github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m
http://pypi.org/project/httplib2

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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.