CVE-2021-22903

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`.

Category

6.1
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.15%
Vendor Advisory rubyonrails.org
Affected: n/a https://github.com/rails/rails
Published at:
Updated at:

References

Link Tags
https://hackerone.com/reports/1148025 third party advisory permissions required
https://discuss.rubyonrails.org/t/cve-2021-22903-possible-open-redirect-vulnerability-in-action-pack/77867 patch vendor advisory mitigation

Frequently Asked Questions

What is the severity of CVE-2021-22903?
CVE-2021-22903 has been scored as a medium severity vulnerability.
How to fix CVE-2021-22903?
To fix CVE-2021-22903, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-22903 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-22903 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-22903?
CVE-2021-22903 affects n/a https://github.com/rails/rails.
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