OAuth Single Sign On – SSO (OAuth Client) < 6.26.13 - Cross-Site Request Forgery

Description

The OAuth Single Sign On – SSO (OAuth Client) plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 6.26.12. This is due to using a predictable state parameter (base64 encoded app name) without any randomness in the OAuth flow. This makes it possible for unauthenticated attackers to forge OAuth authorization requests and potentially hijack the OAuth flow via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.