#VU23007 Input validation error in Ruby - CVE-2019-16201

Vulnerability identifier: #VU23007

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-16201

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ruby
Universal components / Libraries / Scripting languages

Vendor: Ruby

Description

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

The vulnerability exists due to insufficient validation of user-supplied input within the WEBrick::HTTPAuth::DigestAuth in Ruby due to a regular expression issue. A remote attacker can send a specially crafted request to the application and perform a denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Ruby: 1.6 - 2.6.4

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External links
https://hackerone.com/reports/661722
https://www.ruby-lang.org/en/news/2019/10/01/webrick-regexp-digestauth-dos-cve-2019-16201/

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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.