CVE-2022-23527: mod_auth_openidc is an OpenID Certified™ authentication and authorization module for the Apache 2.x HTTP server. Versions prior to 2.4.12.2 are vulner...

Description

mod_auth_openidc is an OpenID Certified™ authentication and authorization module for the Apache 2.x HTTP server. Versions prior to 2.4.12.2 are vulnerable to Open Redirect. When providing a logout parameter to the redirect URI, the existing code in oidc_validate_redirect_url() does not properly check for URLs that start with /\t, leading to an open redirect. This issue has been patched in version 2.4.12.2. Users unable to upgrade can mitigate the issue by configuring mod_auth_openidc to only allow redirection when the destination matches a given regular expression with OIDCRedirectURLsAllowed.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.91%

55.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Openidc	Mod Auth Openidc	< 2.4.12.2
Debian	Debian Linux	10.0

References

Timeline

Published: Dec 14, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-23527?

mod_auth_openidc is an OpenID Certified™ authentication and authorization module for the Apache 2.x HTTP server. Versions prior to 2.4.12.2 are vulnerable to Open Redirect. When providing a logout parameter to the redirect URI, the existing code in oidc_validate_redirect_url() does not properly check for URLs that start with /\t, leading to an open redirect. This issue has been patched in version 2.4.12.2. Users unable to upgrade can mitigate the issue by configuring mod_auth_openidc to only allow redirection when the destination matches a given regular expression with OIDCRedirectURLsAllowed.

How severe is CVE-2022-23527?

CVE-2022-23527 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.91% probability of exploitation in the next 30 days.

How do I fix CVE-2022-23527?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.