CVE & CISA-KEV Catalog

CVE-2021-22903

MEDIUM
6.1
CVSS v3
NVD

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`.

CWE-601Open Redirect

How to fix

Remediation Available
railsNVD
Affected:>= 6.1.1, < 6.1.3.2Fixed in:6.1.3.2CVE-2021-22903derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged

Impact

ConfidentialityLow
IntegrityLow
AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Exploit Intelligence

1.22%probability of exploitation in 30 days
65thpercentile

Moderate risk: more likely to be exploited than 65% of all known CVEs.

References

Third-Party Advisory1

Related Vulnerabilities

Other CWE-601 (Open Redirect) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2025-4123High7.698%-Fix
CVE-2018-11784Medium4.394%-Fix
CVE-2021-22881Medium6.187%-Fix
CVE-2022-45402Medium6.182%-Fix
CVE-2017-1000117High8.878%-Fix
CVE-2019-10098Medium6.174%-Fix
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Markdown

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HTML

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.