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 by DigitialPixies WordPress plugin through 1.1.0 does not sanitize and escapes some of its settings, which could allow high-privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example, in multisite setup).

The OAuth Client by DigitialPixies WordPress plugin through 1.1.0 does not have CSRF checks in some places, which could allow attackers to make logged-in users perform unwanted actions.

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

Authentication Bypass vulnerability in miniOrange OAuth 2.0 client for SSO plugin <= 1.11.3 at WordPress.

The vulnerability is that IDToken verifier does not verify if token is properly signed. Signature verification makes sure that the token's payload comes from valid provider, not from someone else. An attacker can provide a compromised token with custom payload. The token will pass the validation on the client side. We recommend upgrading to version 1.33.3 or above

PKCE support is not implemented in accordance with the RFC for OAuth 2.0 for Native Apps. Without the use of PKCE, the authorization code returned by an authorization server is not enough to guarantee that the client that issued the initial authorization request is the one that will be authorized. An attacker is able to obtain the authorization code using a malicious app on the client-side and use it to gain authorization to the protected resource. This affects the package com.google.oauth-client:google-oauth-client before 1.31.0.