What’s Vulnerable › Vulnerabilities

CVE-2022-23527: Open Redirect in oidc_validate_redirect_url()

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-12-14 · updated 2026-06-17
• Weakness: CWE-601

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.

Affected products

• Debian Linux: 10.0
• OpenIDC mod_auth_openidc: before 2.4.12.2 — fixed in 2.4.12.2

How to fix

Upgrade to a fixed version: OpenIDC mod_auth_openidc 2.4.12.2. Check the vendor advisory for mitigations.

References

• https://github.com/zmartzone/mod_auth_openidc/blob/v2.4.12.1/auth_openidc.conf#L975-L984
• https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-q6f2-285m-gr53
• https://lists.debian.org/debian-lts-announce/2023/07/msg00020.html
• https://github.com/zmartzone/mod_auth_openidc/blob/v2.4.12.1/auth_openidc.conf#L975-L984
• https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-q6f2-285m-gr53
• https://lists.debian.org/debian-lts-announce/2023/07/msg00020.html

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