OpenIDC mod_auth_openidc 2.4.15.2 information disclosure

Summaryinfo

A vulnerability was found in OpenIDC mod_auth_openidc. It has been declared as problematic. Affected by this issue is some unknown functionality. Executing a manipulation can lead to information disclosure. This vulnerability appears as CVE-2025-31492. The attack may be performed from remote. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenIDC mod_auth_openidc. It has been declared as problematic. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. CVE summarizes:

mod_auth_openidc is an OpenID Certified authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality. Prior to 2.4.16.11, a bug in a mod_auth_openidc results in disclosure of protected content to unauthenticated users. The conditions for disclosure are an OIDCProviderAuthRequestMethod POST, a valid account, and there mustn't be any application-level gateway (or load balancer etc) protecting the server. When you request a protected resource, the response includes the HTTP status, the HTTP headers, the intended response (the self-submitting form), and the protected resource (with no headers). This is an example of a request for a protected resource, including all the data returned. In the case where mod_auth_openidc returns a form, it has to return OK from check_userid so as not to go down the error path in httpd. This means httpd will try to issue the protected resource. oidc_content_handler is called early, which has the opportunity to prevent the normal output being issued by httpd. oidc_content_handler has a number of checks for when it intervenes, but it doesn't check for this case, so the handler returns DECLINED. Consequently, httpd appends the protected content to the response. The issue has been patched in mod_auth_openidc versions >= 2.4.16.11.

The advisory is shared for download at github.com. This vulnerability was named CVE-2025-31492 since 03/28/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

The vulnerability scanner Nessus provides a plugin with the ID 234195 (Linux Distros Unpatched Vulnerability : CVE-2025-31492), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.16.11 eliminates this vulnerability. Applying the patch b59b8ad63411857090ba1088e23fe414c690c127 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (234195) and CERT Bund (WID-SEC-2025-0836). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Red Hat Enterprise Linux
• Debian Linux
• Fedora Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux

Productinfo

Vendor

• OpenIDC

Name

• mod_auth_openidc

Version

• 2.4.15.2

License

• open-source

Website

• Product: https://github.com/OpenIDC/mod_auth_openidc/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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