The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
There exists an vulnerability causing an abort() to be called in gRPC.
The following headers cause gRPC's C++ implementation to abort() when called via http2:
te: x (x != trailers)
:scheme: x (x != http, https)
grpclb_client_stats: x (x == anything)
On top of sending one of those headers, a later header must be sent that gets the total header size past 8KB. We recommend upgrading past git commit 2485fa94bd8a723e5c977d55a3ce10b301b437f8 or v1.53 and above.
gRPC contains a vulnerability whereby a client can cause a termination of connection between a HTTP2 proxy and a gRPC server: a base64 encoding error for `-bin` suffixed headers will result in a disconnection by the gRPC server, but is typically allowed by HTTP2 proxies. We recommend upgrading beyond the commit in https://github.com/grpc/grpc/pull/32309 https://www.google.com/url