#VU105106 Input validation error in CGI - CVE-2025-27219

Vulnerability identifier: #VU105106

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-2025-27219

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
CGI
Universal components / Libraries / Programming Languages & Components

Vendor: rubygems.org

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 in CGI::Cookie.parse. A remote attacker can send a specially crafted HTTP request to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

CGI: 0.1.0 - 0.1.1, 0.2.0 - 0.2.2, 0.3.0 - 0.3.6, 0.4.0 - 0.4.1

---

External links
https://www.ruby-lang.org/en/news/2025/02/26/security-advisories/

---

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.