CVE-2021-41816 — Buffer overrun in cgi — CVE Details
Buffer overrun in CGI.escape_html
Summary
Advisory Timeline
- First published December 14, 2021 (1763 days ago).
- Last revised August 13, 2026 — 1703 days after initial publication.
Remediation
Upgrade to the fixed version using your package manager.
gem install cgi -v 0.2.1
gem install cgi -v 0.1.0.1
gem install cgi -v 0.3.1
After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.
Affected Packages (3)
Affects 1 ecosystem: rubygems (1).
Vulnerability Classification
Common Weakness Enumeration (CWE) identifiers for this vulnerability type.
- CWE-190Integer OverflowMITRE
CVSS Score Breakdown
What the CVSS (Common Vulnerability Scoring System) 9.8 score means for each attack dimension.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://nvd.nist.gov/vuln/detail/CVE-2021-41816ADVISORY
- https://github.com/ruby/cgi/commit/959ccf0b6a672bcc64aeaa60c6e1f9e728f1e87fWEB
- https://github.com/ruby/cgi/commit/ad079c1cb5f58eba1ffac46da79995fcf94a3a6eWEB
- https://github.com/ruby/cgi/commit/c6a37a671b556eb06140ea89cc465136b24207a6WEB
- https://github.com/ruby/cgi/commit/c728632c1c09d46cfd4ecbff9caaa3651dd1002aWEB
- https://hackerone.com/reports/1328463WEB
- https://www.ruby-lang.org/en/news/2021/11/24/buffer-overrun-in-cgi-escape_html-cve-2021-41816WEB
- https://security.netapp.com/advisory/ntap-20220303-0006WEB
- https://security.gentoo.org/glsa/202401-27WEB
- https://security-tracker.debian.org/tracker/CVE-2021-41816WEB
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZFWEB
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWNWEB
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZFWEB
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWNWEB
- https://groups.google.com/g/ruby-security-ann/c/4MQ568ZG47cWEB
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2021-41816.ymlWEB
- https://github.com/ruby/cgiPACKAGE
Frequently Asked Questions
- What is CVE-2021-41816?
- Buffer overrun in CGI.escape_html This vulnerability has been assigned a severity rating of CRITICAL (CVSS score: 9.8/10).
- How do I check if my project is affected by CVE-2021-41816?
- CVE-2021-41816 affects cgi. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2021-41816 and 200,000+ other known vulnerabilities.
Severity & Exploitability
Exploitation is straightforward and causes maximum impact. Patch immediately.
Also Known As
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