Package Instance

Connection confusion in gRPC
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.

gRPC Reachable Assertion issue
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.