Affected: Go standard library net/http, golang.org/x/net/http2, go_standard_library net\/http, golang http2

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.

Affected: Go: github.com/moby/spdystream

The SPDY/3 frame parser in spdystream does not validate attacker-controlled counts and lengths before allocating memory. A remote peer that can send SPDY frames to a service using spdystream can cause the process to allocate gigabytes of memory with a small number of malformed control frames, leading to an out-of-memory crash.   Three allocation paths in the receive side are affected: 1. **SETTINGS entry count** -- The SETTINGS frame reader reads a 32-bit `numSettings` from the payload and allocates a slice of that size without checking it against the declared frame length. An attacker can set `numSettings` to a value far exceeding the actual payload, triggering a large allocation before any setting data is read.   2. **Header count** -- `parseHeaderValueBlock` reads a 32-bit `numHeaders` from the decompressed header block and allocates an `http.Header` map of that size with no upper bound.   3. **Header field size** -- Individual header name and value lengths are read as 32-bit integers and used directly as allocation sizes with no validation.   Because SPDY header blocks are zlib-compressed, a small on-the-wire payload can decompress into attacker-controlled bytes that the parser interprets as 32-bit counts and lengths. A single crafted frame is enough to exhaust process memory. ## Impact  Any program that accepts SPDY connections using spdystream -- directly or through a dependent library -- is affected. A remote peer that can send SPDY frames to the service can crash the…