CVE-2023-33953

gRPC has a vulnerability linked to hpack table accounting errors, causing potential unwanted disconnects between clients and servers. Identified vectors include unbounded memory buffering and CPU consumption within the HPACK parser, leading to denial-of-service (DOS) attacks. The CPU issue stems from excessive copying, resulting in inefficient parsing. Memory issues arise from delayed header size checks, allowing large strings to be buffered, and a quirk in HPACK's integer encoding, permitting infinite zero-padding. Additionally, metadata overflow checks per frame could enable infinite buffering, compromising gRPC's stability and security.