CVE-2021-22903

medium
Published 2021-05-05 · Modified 2024-02-16
CVSS v3
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v2
VIR risk
5.5

Description

The actionpack ruby gem before 6.1.3.2 suffers from a possible open redirect vulnerability. Specially crafted Host headers in combination with certain "allowed host" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website. This is similar to CVE-2021-22881. Strings in config.hosts that do not have a leading dot are converted to regular expressions without proper escaping. This causes, for example, `config.hosts << "sub.example.com"` to permit a request with a Host header value of `sub-example.com`.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-22903

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-22903.html

OS impact

OSVersionStatusFixed in
arch archaffected
suse slesaffected
debian debianbookwormfixed0
debian debianbullseyefixed0
debian debianforkyfixed0
debian debiansidfixed0
debian debiantrixiefixed0

Package impact

EcosystemPackageVulnerableFixed
ruby RubyGemsactionpack!< 6.1.0.rc2||<>= 6.1.3.2>= 6.1.3.2
ruby RubyGemsactionpack>=6.1.0.rc2,<6.1.3.26.1.3.2

References

Verify integrity in audit chain (admin only). AS-IS.