Cross-Site Request Forgery (CSRF) in the Planet feed aggregator administration of Apache Roller 4.0 through 6.1.6 allows an unauthenticated attacker to make the Roller server fetch a URL the attacker chooses, including internal addresses, by inducing a logged-in global administrator to open a crafted web page. The action that adds a Planet subscription can be triggered cross-site; in recent releases it accepts GET requests, which Roller's CSRF token check does not cover. The action fetches the supplied URL and saves the subscription, and any fetched content that parses as a feed is then published without authentication in the aggregated Planet feed. The Planet aggregator is enabled by default. Users are recommended to upgrade to Apache Roller 6.1.7 or later, which requires POST requests with a valid CSRF token for Planet administration changes and turns the Planet aggregator off by default.