The SiteGround Security plugin for WordPress is vulnerable to authentication bypass that allows unauthenticated users to log in as administrative users due to missing identity verification on the 2FA back-up code implementation that logs users in upon success. This affects versions up to, and including, 1.2.5.
WordPress SiteGround Security plugin versions 1.2.5 and below suffer from an authentication bypass vulnerability as well as an authorization weakness in versions 1.2.4 and below.