Is OAuth Single Sign On safe? Known vulnerabilities and latest version

Unauthenticated Bypass Vulnerability in OAuth Single Sign On – SSO (OAuth Client) <= 7.1.2 versions.

The OAuth Single Sign On WordPress plugin before 7.0.1 does not verify the identity assertion returned by its Steam single sign-on flow, allowing unauthenticated attackers to log in as an arbitrary non-administrator user, and to create new accounts.

Unauthenticated Broken Authentication in OAuth Single Sign On – SSO (OAuth Client) <= 7.0.0 versions.

The OAuth Single Sign On – SSO (OAuth Client) plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 6.26.14. This is due to missing capability checks and authentication verification on the OAuth redirect functionality accessible via the 'oauthredirect' option parameter. This makes it possible for unauthenticated attackers to set the global redirect URL option via the redirect_url parameter granted they can access the site directly.

The OAuth Single Sign On – SSO (OAuth Client) plugin for WordPress is vulnerable to Improper Verification of Cryptographic Signature in versions up to, and including, 6.26.12. This is due to the plugin performing unsafe JWT token processing without verification or validation in the `get_resource_owner_from_id_token` function. This makes it possible for unauthenticated attackers to bypass authentication and gain access to any existing user account - including administrators in certain configurations - or to create arbitrary subscriber-level accounts.

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.

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.

Improper Authentication vulnerability in miniOrange OAuth Single Sign On – SSO (OAuth Client) plugin allows Authentication Bypass.This issue affects OAuth Single Sign On – SSO (OAuth Client): from n/a through 6.23.3.

The OAuth Single Sign On WordPress plugin before 6.24.2 does not have CSRF checks when discarding Identify providers (IdP), which could allow attackers to make logged in admins delete all IdP via a CSRF attack

The OAuth Single Sign On WordPress plugin before 6.22.6 doesn't validate that OAuth access token requests are legitimate, which allows attackers to log onto the site with the only knowledge of a user's email address.