Lighttpd must prevent hosted applications from exhausting system resources.

When it comes to DoS attacks, most of the attention is paid to ensuring that systems and applications are not victims of these attacks. While it is true that those accountable for systems want to ensure they are not affected by a DoS attack, they also need to ensure their systems and applications are not used to launch such an attack against others. To that extent, a variety of technologies exist to limit, or in some cases, eliminate the effects of DoS attacks. Limiting system resources that are allocated to any user to a bare minimum may also reduce the ability of users to launch some DoS attacks. Applications and application developers must take the steps needed to ensure users cannot use these applications to launch DoS attacks against other systems and networks.

An example would be preventing Lighttpd from keeping idle connections open for too long.