Unbounded chunk-size hex digits in cowlib cause quadratic CPU and memory DoS

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion.

cowspdy:inflate/2 in cowlib passes peer-supplied compressed bytes directly to zlib:inflate/2 with no output size bound. The SPDY header compression dictionary (?ZDICT) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for synstream, synreply, and headers frame types are all affected via cowspdy:parseheaders/2.

This issue affects cowlib from 0.1.0 before 2.16.1.

CR Injection in SSE Encoder Enables Event Splitting via cowsse:event/1

HTTP Response Splitting via Non-VCHAR Bytes in cowhttpstructhd:escapestring/2