HTTP and MIME header parsing can allocate large amounts
of memory, even when parsing small inputs, potentially
leading to a denial of service. Certain unusual patterns
of input data can cause the common function used to parse
HTTP and MIME headers to allocate substantially more
memory than required to hold the parsed headers. An
attacker can exploit this behavior to cause an HTTP
server to allocate large amounts of memory from a small
request, potentially leading to memory exhaustion and a
denial of service. With fix, header parsing now correctly
allocates only the memory required to hold parsed headers.