Vulnerability identifier: #VU76185

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-2021-3803

CWE-ID: CWE-185

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
nth-check
Web applications / JS libraries

Vendor: fb55

Description

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

The vulnerability exists due to insufficient input validation when processing regular expressions. A remote attacker can pass specially crafted data to the application and perform regular expression denial of service (ReDos) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

nth-check: 1.0.2 - 2.0.0

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External links
http://github.com/fb55/nth-check/commit/9894c1d2010870c351f66c6f6efcf656e26bb726
http://huntr.dev/bounties/8cf8cc06-d2cf-4b4e-b42c-99fafb0b04d0

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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.