bozotic HTTP server (aka bozohttpd) before 20100621 allows remote attackers to list the contents of home directories, and determine the existence of user accounts, via multiple requests for URIs beginning with /~ sequences.
https://exchange.xforce.ibmcloud.com/vulnerabilities/60812
https://euvd.enisa.europa.eu/vulnerability/EUVD-2010-2330
https://bugs.launchpad.net/ubuntu/+source/bozohttpd/+bug/582473
http://www.eterna.com.au/bozohttpd/CHANGES
http://security-tracker.debian.org/tracker/CVE-2010-2320