HTTP File Server (HFS) before 2.2c allows remote attackers to obtain configuration and usage details by using an id element such as <id>%version%</id> in HTTP Basic Authentication instead of a username and password, as demonstrated by placing this id element in the userinfo subcomponent of a URL.
https://exchange.xforce.ibmcloud.com/vulnerabilities/39871
http://www.syhunt.com/advisories/hfshack.txt
http://www.syhunt.com/advisories/hfs-1-template.txt
http://www.securityfocus.com/bid/27423
http://www.securityfocus.com/archive/1/486872/100/0/threaded