CVE-2021-41816
9.8
CRITICAL · CVSS 3.1 · EPSS 4.9% (pctl 92)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
Description
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.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 4.9% — more likely to be exploited than 92% of all CVEs |
| Weakness | CWE-190 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2022-02-06 |
| Last modified | 2026-06-17 |
Affected (3)
| Vendor | Product |
|---|---|
| fedoraproject | fedora |
| ruby-lang | cgi |
| ruby-lang | ruby |
References
- https://hackerone.com/reports/1328463
- 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-2021-41816
- https://security.gentoo.org/glsa/202401-27
- https://security.netapp.com/advisory/ntap-20220303-0006/
- https://www.ruby-lang.org/en/news/2021/11/24/buffer-overrun-in-cgi-escape_html-cve-2021-41816/
- https://hackerone.com/reports/1328463
- 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-2021-41816
- https://security.gentoo.org/glsa/202401-27
- https://security.netapp.com/advisory/ntap-20220303-0006/
- https://www.ruby-lang.org/en/news/2021/11/24/buffer-overrun-in-cgi-escape_html-cve-2021-41816/
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