CVE-2021-44528: Medium severity ruby on rails vulnerability
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.
Other sources
Specially crafted "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.
Impacted applications will have allowed hosts with a leading dot. For example, configuration files that look like this:
config.hosts << '.EXAMPLE.com'
When an allowed host contains a leading dot, a specially crafted Host header can be used to redirect to a malicious website.
This vulnerability is similar to CVE-2021-22881 and CVE-2021-22942.
Releases -------- The fixed releases are available at the normal locations.
Patches ------- To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset.
6-0-host-authorzation-open-redirect.patch - Patch for 6.0 series 6-1-host-authorzation-open-redirect.patch - Patch for 6.1 series 7-0-host-authorzation-open-redirect.patch - Patch for 7.0 series
Please note that only the 6.1.Z, 6.0.Z, and 5.2.Z series are supported at present. Users of earlier unsupported releases are advised to upgrade as soon as possible as we cannot guarantee the continued availability of security fixes for unsupported releases.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2021-44528?
CVE-2021-44528 is an open redirect vulnerability in Action Pack, a component of Ruby on Rails.
How does CVE-2021-44528 work?
CVE-2021-44528 can be exploited by an attacker using specially crafted "X-Forwarded-Host" headers in combination with certain "allowed host" formats to redirect users to a malicious website.
Which applications are impacted by CVE-2021-44528?
Applications using Action Pack versions between 6.0.0 and 6.0.4.1 or between 6.1.0 and 6.1.4.1 may be impacted by CVE-2021-44528.
How severe is CVE-2021-44528?
CVE-2021-44528 has a severity rating of 6.1 (High).
What is the remedy for CVE-2021-44528?
To mitigate CVE-2021-44528, upgrade to version 6.0.4.2 or 6.1.4.2 of Action Pack, which contain the necessary fixes.