CVE-2021-32786
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.
EPSS 0.12% · 30.0th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:20.04:LTS | libapache2-mod-auth-openidc | 2.3.10.2-1, 2.4.0.4-1, 2.4.1-1 |
| Ubuntu:18.04:LTS | libapache2-mod-auth-openidc | 0, 2.1.6-1, 2.3.1-2 |
Timeline
- Jul 22, 2021 CVE Published
- Jul 23, 2021 EPSS Score
- Aug 5, 2021 EPSS Score
- Sep 2, 2021 EPSS Score
- Sep 20, 2021 EPSS Score
- Nov 19, 2021 EPSS Score
- Jan 17, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Mar 17, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- Jul 15, 2022 EPSS Score
- Sep 12, 2022 EPSS Score
References
- https://ubuntu.com/security/CVE-2021-32786 third-party-advisory
- https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-xm4c-5wm5-jqv7 third-party-advisory
- https://github.com/zmartzone/mod_auth_openidc/commit/3a115484eb927bc6daa5737dd84f88ff4bbc5544 third-party-advisory
- https://daniel.haxx.se/blog/2017/01/30/one-url-standard-please/ third-party-advisory
- https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9 third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-32786 third-party-advisory