mod_userdir in lighttpd 1.4.18 and earlier, when userdir.path is not set, uses a default of $HOME, which might allow remote attackers to read arbitrary files, as demonstrated by accessing the ~nobody directory.
https://exchange.xforce.ibmcloud.com/vulnerabilities/41173
https://bugs.gentoo.org/show_bug.cgi?id=212930
http://www.vupen.com/english/advisories/2008/0885/references
http://www.securityfocus.com/bid/28226
http://www.securityfocus.com/archive/1/489465/100/0/threaded
http://www.lighttpd.net/security/lighttpd_sa_2008_03.txt
http://www.lighttpd.net/2008/3/10/1-4-19-made-in-germany
http://www.debian.org/security/2008/dsa-1521
http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0106
http://trac.lighttpd.net/trac/ticket/1587
http://security.gentoo.org/glsa/glsa-200804-08.xml
http://secunia.com/advisories/29636
http://secunia.com/advisories/29622
http://secunia.com/advisories/29403
http://secunia.com/advisories/29318
http://lists.opensuse.org/opensuse-security-announce/2008-04/msg00005.html