Lighttpd

I noticed that "follow symlinks" is enabled by default even if userdirs are enabled.
This of course should never happen, since it gives to every user access to read any file that can be read by www-data.
Hints:
social_engineer@badhost:~public_html$ ln -s /path/to/file.php file.txt
social_engineer@badhost:~public_html$ ln -s /etc

IMAO you should either disallow having both options enabled, or at least check if the owner matches before following a symlink. By default. (apache has such an option but couldn't find it here).