Input validation vulnerability in SAML Single Sign On – SSO Login 4.9.20

The SAML Single Sign On – SAML SSO Login plugin for WordPress has a security issue that could let unauthenticated attackers inject malicious web scripts into pages that execute. This vulnerability is present in versions up to and including 4.9.20 and is caused by the use of the add_query_arg function on the URL without appropriate escaping. In order to exploit this issue, an attacker would have to convince a user to click on a malicious link.