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.
response.c in Lighttpd 1.4.10 and possibly previous versions, when run on Windows, allows remote attackers to read arbitrary source code via requests that contain trailing (1) "." (dot) and (2) space characters, which are ignored by Windows, as demonstrated by PHP files.
LightTPD 1.4.8 and earlier, when the web root is on a case-insensitive filesystem, allows remote attackers to bypass URL checks and obtain sensitive information via file extensions with unexpected capitalization, as demonstrated by a request for index.PHP when the configuration invokes the PHP interpreter only for ".php" names.