Jenkins Google Login Plugin 1.7 and earlier uses a non-constant time comparison function when checking whether the provided and expected token are equal, potentially allowing attackers to use statistical methods to obtain a valid token.
The Google Login Plugin (versions 1.0 and 1.1) allows malicious anonymous users to authenticate successfully against Jenkins instances that are supposed to be locked down to a particular Google Apps domain through client-side request modification.
A session fixaction vulnerability exists in Jenkins Google Login Plugin 1.3 and older in GoogleOAuth2SecurityRealm.java that allows unauthorized attackers to impersonate another user if they can control the pre-authentication session.
An open redirect vulnerability exists in Jenkins Google Login Plugin 1.3 and older in GoogleOAuth2SecurityRealm.java that allows attackers to redirect users to an arbitrary URL after successful login.