lighttpd before 1.4.14 allows attackers to cause a denial of service (crash) via a request to a file whose mtime is 0, which results in a NULL pointer dereference.

lighttpd 1.4.12 and 1.4.13 allows remote attackers to cause a denial of service (cpu and resource consumption) by disconnecting while lighttpd is parsing CRLF sequences, which triggers an infinite loop and file descriptor consumption.

lighttpd before 1.4.26, and 1.5.x, allocates a buffer for each read operation that occurs for a request, which allows remote attackers to cause a denial of service (memory consumption) by breaking a request into small pieces that are sent at a slow rate.

The configuration file for the FastCGI PHP support for lighttpd before 1.4.28 on Debian GNU/Linux creates a socket file with a predictable name in /tmp, which allows local users to hijack the PHP control socket and perform unauthorized actions such as forcing the use of a different version of PHP via a symlink attack or a race condition.