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CVE-2021-44528

33
FAUCET Score

CVE-2021-44528 is an open redirect vulnerability affecting Action Pack versions 6.0.0 and above, a component of Ruby on Rails. An attacker can manipulate the "X-Forwarded-Host" header in conjunction with specific "allowed host" configurations to redirect users to malicious websites. This vulnerability has a CVSS score of 6.1 (Medium), indicating a network-based attack with low complexity, requiring user interaction, and potentially leading to information disclosure and integrity impacts. While there is no evidence of active exploitation or Metasploit/ExploitDB modules, Nuclei templates exist, and the vulnerability has a high FAUCET Risk Score, but has received minimal community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
6.0.4.2CPE matchmatch criteria
cpe:2.3:a:rubyonrails:rails:6.0.4.2:*:*:*:*:*:*:*
6.1.4.2CPE matchmatch criteria
cpe:2.3:a:rubyonrails:rails:6.1.4.2:*:*:*:*:*:*:*
7.0.0CPE matchmatch criteria
cpe:2.3:a:rubyonrails:rails:7.0.0:rc2:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.1MEDIUM

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
Exploitability Score
2.8
Impact Score
2.7
CvssVersion
3.1

Exploit Intelligence

EPSS Score
4.18%
Probability of exploitation in next 30 days
EPSS Percentile
89.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Nuclei: CVE-2021-44528 · Dec 15, 2021
This CVE's current EPSS score of 0.0418 is in the 96th percentile among its peer group of 26,234 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (3)

github_advisorypatch availablevia nvd_reference
View patch
rubygemspatch availablevia ghsa
Product: actionpackFixed in: 6.0.4.2
rubygemspatch availablevia ghsa
Product: actionpackFixed in: 6.1.4.2

Vendor Advisories (2)

rubygemsGHSA-qphc-hf5q-v8fcmedium

actionpack Open Redirect in Host Authorization Middleware

Dec 14, 2021
redhatCVE-2021-44528Moderate

rubygem-actionpack: specially crafted "X-Forwarded-Host" headers may lead to open redirect

Dec 14, 2021

References

github.com / rails/rails/commit/0fccfb9a3097a9c4260c791f1a40b128517e7815
PatchThird Party Advisory
security.netapp.com / advisory/ntap-20240208-0003
debian.org / security/2023/dsa-5372