thttpd HTTP server 2.03 and earlier allows remote attackers to read arbitrary files via a GET request with more than one leading / (slash) character in the filename.
https://exchange.xforce.ibmcloud.com/vulnerabilities/1809
http://www.securityfocus.com/archive/1/10368
http://www.acme.com/software/thttpd/thttpd.html#releasenotes