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