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/33005 https://github.com/grpc/grpc/pull/33005
Exploitability
AV:NAC:HPR:NUI:NScope
S:UImpact
C:HI:NA:H7.4/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:HOther