The SSO login page is hosted on WebLogic Application Server. The credentials entered on the login page are submitted to login.fcc hosted on Web Agent installed on Web Server. Hence the login page is vulnerable to CSRF attack.
To solve this issue, see "Vulnerability 4: Cross-Site Request Forgery (XSRF/CSRF)" (1).
From the above, see "Use a Relative Target for Credential Collector Redirects" and "Define Valid Target Domains" for more information on ValidTargetDomain and TargetAsRelativeURI (2).
Also, see "Prevent Cross-Site Scripting Attacks in Web Agent FCC Pages" (3).