UMich OIDC Login WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the UMich OIDC Login plugin for WordPress, affecting all versions up to and including 1.2.0. The vulnerability arises from inadequate input sanitization and output escaping of user-supplied attributes in the 'umich_oidc_button' shortcode. This flaw allows authenticated attackers with contributor-level access or higher to inject arbitrary web scripts into pages, which are executed when users access the affected pages.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the page.

Reproduction

To reproduce this vulnerability, an authenticated user with contributor-level access or higher can use the 'umich_oidc_button' shortcode to inject a script. The absence of proper input sanitization and output escaping on the shortcode's attributes enables the injection of malicious scripts that will be executed when the page is viewed.

Remediation

No known patch is available. It is recommended to review the vulnerability details and consider uninstalling the affected plugin.