The remote host is missing an update to lighttpd announced via advisory DSA 1987-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201987-1

Li Ming discovered that lighttpd, a small and fast webserver with minimal memory footprint, is vulnerable to a denial of service attack due to bad memory handling. Slowly sending very small chunks of request data causes lighttpd to allocate new buffers for each read instead of appending to old ones. An attacker can abuse this behaviour to cause denial of service conditions due to memory exhaustion. For the oldstable distribution (etch), this problem has been fixed in version 1.4.13-4etch12. For the stable distribution (lenny), this problem has been fixed in version 1.4.19-5+lenny1. For the testing (squeeze) and unstable (sid) distribution, this problem will be fixed soon. We recommend that you upgrade your lighttpd packages.