Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Drupal OAuth & OpenID Connect Single Sign On – SSO (OAuth/OIDC Client) allows Cross-Site Scripting (XSS).This issue affects OAuth & OpenID Connect Single Sign On – SSO (OAuth/OIDC Client): from 3.0.0 before 3.44.0, from 4.0.0 before 4.0.19.

The OAuth Single Sign On – SSO (OAuth Client) plugin for WordPress is vulnerable to authentication bypass in all versions up to, and including, 6.26.3. This is due to insufficient verification on the user being returned by the social login token. This makes it possible for unauthenticated attackers to log in as any existing user on the site, such as an administrator, if they have access to the username and the user does not have an already-existing account for the service returning the token.

The OAuth client Single Sign On WordPress plugin before 3.0.4 does not have authorisation and CSRF when updating its settings, which could allow unauthenticated attackers to update them and change the OAuth endpoints to ones they controls, allowing them to then be authenticated as admin if they know the correct email address