ruby/cgi · Security
CGI has Denial of Service (DoS) potential in Cookie.parse
- GHSA ID
- GHSA-gh9q-2xrm-x6qv
- CVE ID
- CVE-2025-27219
- Severity
- medium
- Published
- Updated
- CVSS
- 5.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
- CVSS v3
- 5.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
- CVSS v4
- 6.3 · CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Description
There is a possibility for DoS by in the cgi gem. This vulnerability has been assigned the CVE identifier CVE-2025-27219. We recommend upgrading the cgi gem.
Details
CGI::Cookie.parse took super-linear time to parse a cookie string in some cases. Feeding a maliciously crafted cookie string into the method could lead to a Denial of Service.
Please update CGI gem to version 0.3.5.1, 0.3.7, 0.4.2 or later.
Affected versions
cgi gem versions <= 0.3.5, 0.3.6, 0.4.0 and 0.4.1.
Credits
Thanks to lio346 for discovering this issue. Also thanks to mame for fixing this vulnerability.
CWEs
- CWE-400 · Uncontrolled Resource Consumption
- CWE-770 · Allocation of Resources Without Limits or Throttling
References
- https://github.com/ruby/cgi/pull/52 ↗
- https://github.com/ruby/cgi/pull/53 ↗
- https://github.com/ruby/cgi/pull/54 ↗
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27219.yml ↗
- https://www.cve.org/CVERecord?id=CVE-2025-27219 ↗
- https://nvd.nist.gov/vuln/detail/CVE-2025-27219 ↗
- https://hackerone.com/reports/2936778 ↗
- https://lists.debian.org/debian-lts-announce/2025/03/msg00008.html ↗
- https://github.com/advisories/GHSA-gh9q-2xrm-x6qv ↗