title: Information leak in gRPC
description: 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
problem types: CWE-440: Expected Behavior Violation
affected:
{
defaultStatus: unaffected
product: gRPC
repo: https://github.com/grpc
vendor: Google
versions:
lessThanOrEqual: 1.54, status: affected, version: 1.53, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.4
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL
solutions: Fixes available in these releases:
- 1.52.2:  https://github.com/grpc/grpc/releases/tag/v1.52.2 https://github.com/grpc/grpc/releases/tag/v1.52.2
- 1.53.1:  https://github.com/grpc/grpc/releases/tag/v1.53.1 https://github.com/grpc/grpc/releases/tag/v1.53.1
- 1.54.2:  https://github.com/grpc/grpc/releases/tag/v1.54.2 https://github.com/grpc/grpc/releases/tag/v1.54.2
- 1.55.0:  https://github.com/grpc/grpc/releases/tag/v1.55.0 https://github.com/grpc/grpc/releases/tag/v1.55.0