Vulnerability identifier: #VU25628

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-2020-5243

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
uap-core
Web applications / Modules and components for CMS

Vendor: ua-parser

Description

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

The vulnerability exists due to overlapping capture groups when processing crafted User-Agent strings. A remote attacker can overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings, trigger resource exhaustion and perform a regular expression denial of service (REDoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

uap-core: 0.1.0 - 0.7.2

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External links
http://github.com/ua-parser/uap-core/commit/0afd61ed85396a3b5316f18bfd1edfaadf8e88e1
http://github.com/ua-parser/uap-core/security/advisories/GHSA-cmcx-xhr8-3w9p

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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.