#VU55667 Resource exhaustion in UAParser.js - CVE-2021-27292

Vulnerability identifier: #VU55667

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-2021-27292

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
UAParser.js
Web applications / JS libraries

Vendor: Faisal Salman

Description

The vulnerability allows a remote attacker to perform a regular expression denial of service (ReDoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources when processing a malicious User-Agent header. A remote attacker can trigger resource exhaustion and perform a regular expression denial of service (ReDoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

UAParser.js: 0.7.14 - 0.7.23

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External links
https://gist.github.com/b-c-ds/6941d80d6b4e694df4bc269493b7be76
https://github.com/faisalman/ua-parser-js/commit/809439e20e273ce0d25c1d04e111dcf6011eb566
https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14

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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.