Cross-site request forgery (CSRF) vulnerability in the Calendar plugin before 1.3.3 for WordPress allows remote attackers to hijack the authentication of users for requests that add a calendar entry via unspecified vectors.
https://exchange.xforce.ibmcloud.com/vulnerabilities/84032
https://euvd.enisa.europa.eu/vulnerability/EUVD-2013-2637
http://www.securityfocus.com/bid/59661