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CVE-2021-32786

Open Redirect in oidc_validate_redirect_url()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 2.4.9
None on Exploit-DB, Metasploit or GitHub

Summary

mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In versions prior to 2.4.9, `oidc_validate_redirect_url()` does not parse URLs the same way as most browsers do. As a result, this function can be bypassed and leads to an Open Redirect vulnerability in the logout functionality. This bug has been fixed in version 2.4.9 by replacing any backslash of the URL to redirect with slashes to address a particular breaking change between the different specifications (RFC2396 / RFC3986 and WHATWG). As a workaround, this vulnerability can be mitigated by configuring `mod_auth_openidc` to only allow redirection whose destination matches a given regular expression.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • zmartzone mod_auth_openidc

    fixed in 2.4.9

References 9

GitHub · zmartzone/mod_auth_openidc

daniel.haxx.se

lists.fedoraproject.org

oracle.com

security.netapp.com

lists.debian.org