nessusd_www_server.nbin in the Nessus Web Server plugin 1.2.4 for Nessus allows remote attackers to obtain sensitive information via a request to the /feed method, which reveals the version in a response.
https://discussions.nessus.org/message/7245#7245
http://www.securityfocus.com/archive/1/512645/100/0/threaded