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URL Redirection to Untrusted Site ('Open Redirect')

CVE-2021-22903

Medium
6.1/10

Summary

The actionpack ruby gem versions from 6.1.0.rc2 through 6.1.3.1 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`.

  • LOW
  • NETWORK
  • LOW
  • CHANGED
  • REQUIRED
  • NONE
  • LOW
  • NONE

CWE-601 - Open Redirect

An open redirect attack employs a URL parameter, HTML refresh tags, or a DOM based location change to exploit the trust of a vulnerable domain to direct the users to a malicious website. The attack could lead to higher severity vulnerabilities such as unauthorized access control, account takeover, XSS, and more.

References

Advisory Timeline

  • Published