Open Redirect is a vulnerability by which a web application fails to authenticate URLs. This will lead to attackers directing the end users to malicious sites to extract information.
Server that uses a vulnerable version of WordPress(2.9.2-4.8.1). It can be vulnerable to an open redirect attack. It could easily be done in user edit and edit tag form. Unvalidated Redirects and Forwards by this server allow redirecting a user to a new website without any proper validation of the target redirect.