CVE-2025-27219

MEDIUM

CGI gem < 0.4.2 - Denial of Service via Unbounded Cookie Value Parsing

Title source: llm

Description

In the CGI gem before 0.4.2 for Ruby, the CGI::Cookie.parse method in the CGI library contains a potential Denial of Service (DoS) vulnerability. The method does not impose any limit on the length of the raw cookie value it processes. This oversight can lead to excessive resource consumption when parsing extremely large cookies.

References (3)

Core 3

Core References

Mailing List

https://lists.debian.org/debian-lts-announce/2025/03/msg00008.html

Third Party Advisory

https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27219.yml

View Writeup ZIP pw:eip

Permissions Required

https://hackerone.com/reports/2936778

Scores

CVSS v3 5.8

EPSS 0.0032

EPSS Percentile 54.7%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-770

Status published

Products (3)

ruby-lang/cgi 0.3.6

ruby-lang/cgi < 0.3.5.1

rubygems/cgi 0 - 0.3.5.1RubyGems

Published Mar 04, 2025

Tracked Since Feb 18, 2026