7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
0.002 Low
EPSS
Percentile
56.4%
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