CVE-2021-41816

CGI.escape_html in Ruby before 2.7.5 and 3.x before 3.0.3 has an integer overflow and resultant buffer overflow via a long string on platforms (such as Windows) where size_t and long have different numbers of bytes. This also affects the CGI gem before 0.3.1 for Ruby.

• CWE-190

• https://hackerone.com/reports/1328463Permissions Required, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/
• https://security-tracker.debian.org/tracker/CVE-2021-41816Third Party Advisory
• https://security.gentoo.org/glsa/202401-27
• https://security.netapp.com/advisory/ntap-20220303-0006/Third Party Advisory
• https://www.ruby-lang.org/en/news/2021/11/24/buffer-overrun-in-cgi-escape_html-cve-2021-41816/Exploit, Vendor Advisory
• https://hackerone.com/reports/1328463Permissions Required, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/
• https://security-tracker.debian.org/tracker/CVE-2021-41816Third Party Advisory
• https://security.gentoo.org/glsa/202401-27
• https://security.netapp.com/advisory/ntap-20220303-0006/Third Party Advisory
• https://www.ruby-lang.org/en/news/2021/11/24/buffer-overrun-in-cgi-escape_html-cve-2021-41816/Exploit, Vendor Advisory

Published

Feb 6, 2022

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-41805HashiCorp Consul Enterprise before 1.8.17, 1.9.x before 1.9.…8.8
• CVE-2021-41807Lack of rate limiting in M-Files Server and M-Files Web prod…9.8
• CVE-2021-41808In M-Files Server product with versions before 21.11.10775.0…2.3
• CVE-2021-41809SSRF vulnerability in M-Files Server products with versions …4.3
• CVE-2021-4181Crash in the Sysdig Event dissector in Wireshark 3.6.0 and 3…7.5
• CVE-2021-41810Script injection in M-Files Admin versions before 22.2.11051…4.8
• CVE-2021-41817Date.parse in the date gem through 3.2.0 for Ruby allows ReD…7.5
• CVE-2021-41819CGI::Cookie.parse in Ruby through 2.6.8 mishandles security …7.5
• CVE-2021-4182Crash in the RFC 7468 dissector in Wireshark 3.6.0 and 3.4.0…7.5
• CVE-2021-41821Wazuh Manager in Wazuh through 4.1.5 is affected by a remote…6.5
• CVE-2021-41823The Web Application Firewall (WAF) in Kemp LoadMaster 7.2.54…6.1
• CVE-2021-41824Craft CMS before 3.7.14 allows CSV injection.8.8