When gRPC HTTP2 stack raised a header size exceeded error, it
skipped parsing the rest of the HPACK frame. This caused any HPACK
table mutations to also be skipped, resulting in a desynchronization
of HPACK tables between sender and receiver. If leveraged, say,
between a proxy and a backend, this could lead to requests from the
proxy being interpreted as containing headers from different
proxy clients
– leading to an information leak that can be used for privilege
escalation or data exfiltration. We recommend upgrading beyond
the commit contained in https://github.com/grpc/grpc/pull/32309Read More
Connection confusion in gRPC
