🛡️ CVE-2021-33621 on Debian — ruby2.7

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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.

Distribution advisory

This page covers CVE-2021-33621 as tracked by Debian, for the package ruby2.7. The fix is available in version 2.7.4-1+deb11u2; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Affected software

DEBIAN-CVE-2021-33621 is recorded against 2 packages.

  • ruby2.7 (fixed in 2.7.4-1+deb11u2)
  • ruby3.1 (fixed in 3.1.2-4)

Timeline and source

Published on 18 November 2022 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2021-33621 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2022-11-18
Updated 2026-08-11
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
ruby2.7 — 2.7.4-1+deb11u2
ruby3.1 — 3.1.2-4

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