GHSA-vc47-6rqg-c7f5 · Severity: high · Ecosystem: rubygems — HTTP response splitting in CGI
The cgi gem before 0.1.0.2, 0.2.x before 0.2.2, and 0.3.x before 0.3.5 for Ruby allows HTTP response splitting. This is relevant to applications that use untrusted user input either to generate an HTTP response or to create a CGI::Cookie object.
Conclusion & alert: CVE-2021-33621 is rated High Exploit Risk (79.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.29%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.19% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 1.10% | 2.29% | +1.19% |
| 2 | 2026-06-08 | 1.01% | 1.10% | +0.09% |
| 3 | 2026-06-04 | — | 1.01% | — |
Full EPSS history (61 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
GHSA-vc47-6rqg-c7f5 · Severity: high · Ecosystem: rubygems — HTTP response splitting in CGI
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2021-33621: 1 source package rows (ruby); 7 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 0. | https://security.alpinelinux.org/vuln/CVE-2021-33621 |
debian
|
not yet assigned | CVE-2021-33621 not yet assigned priority: Debian including 2 source packages (ruby2.7, ruby3.1), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. | https://security-tracker.debian.org/tracker/CVE-2021-33621 |
gentoo
|
normal | CVE-2021-33621: 1 GLSA(s) (202401-27), 1 atom(s) (dev-lang/ruby); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-33621 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2021-33621 |
suse
|
high | CVE-2021-33621 severity important: SUSE including 324 source package names (2.17-17.3:libruby2_5-2_5-2.5.9-150000.4.29.1, 2.17-17.3:ruby2.5-2.5.9-150000.4.29.1, …), 913 product×package rows across 190 product lines (Container bci/ruby, Container suse/rmt-server, … (190 product lines)): Fixed 645, Known Affected 231, Known Not Affected 37. | https://www.suse.com/security/cve/CVE-2021-33621/ |
ubuntu
|
medium | CVE-2021-33621 medium priority: Ubuntu including 8 source packages (jruby, ruby1.9.1, …), 74 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 46, needs-triage 12, released 8, ignored 6, not-affected 2. | https://ubuntu.com/security/CVE-2021-33621 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| ruby-lang | cgi | < 0.1.0.2 | cpe:2.3:a:ruby-lang:cgi:*:*:*:*:*:ruby:*:* |
| ruby-lang | cgi | >= 0.2.0, < 0.2.2 | cpe:2.3:a:ruby-lang:cgi:*:*:*:*:*:ruby:*:* |
| ruby-lang | cgi | >= 0.3.0, < 0.3.5 | cpe:2.3:a:ruby-lang:cgi:*:*:*:*:*:ruby:*:* |
| fedoraproject | fedora | 35 | cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* |
| fedoraproject | fedora | 36 | cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* |
| fedoraproject | fedora | 37 | cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:* |
| ruby-lang | ruby | >= 2.7.0, < 2.7.7 | cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:* |
| ruby-lang | ruby | >= 3.0.0, < 3.0.5 | cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:* |
| ruby-lang | ruby | >= 3.1.0, < 3.1.3 | cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:* |