CVE-2021-32786
4.7 · MEDIUMOverview
CVE-2021-32786 is a medium-severity vulnerability affecting openidc mod_auth_openidc. It was published on July 22, 2021 and has a CVSS 3.1 base score of 4.7 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.7, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
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.
Remediation
Check the references section for vendor advisories and patches from openidc. Update mod_auth_openidc to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| openidc | mod_auth_openidc | >= 0, < 2.4.9 | Affected |
| apache | http_server | 2.0.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-32786?
CVE-2021-32786 is a medium-severity vulnerability affecting openidc mod_auth_openidc. It was published on July 22, 2021 and has a CVSS 3.1 base score of 4.7 (MEDIUM).
How severe is CVE-2021-32786?
This vulnerability has a CVSS 3.1 base score of 4.7, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-32786?
Check the references section for vendor advisories and patches from openidc. Update mod_auth_openidc to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-32786?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-32786 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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