CVE-2023-32732: Denial-of-Service in gRPC

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-06-09 · updated 2026-06-17
Weakness: CWE-440

Description

gRPC contains a vulnerability whereby a client can cause a termination of connection between a HTTP2 proxy and a gRPC server: a base64 encoding error for `-bin` suffixed headers will result in a disconnection by the gRPC server, but is typically allowed by HTTP2 proxies. We recommend upgrading beyond the commit in https://github.com/grpc/grpc/pull/32309 https://www.google.com/url

Affected products

Fedoraproject Fedora: 37, 38
Google gRPC: before 1.53.0 — fixed in 1.53.0

How to fix

Upgrade to a fixed version: Google gRPC 1.53.0. Check the vendor advisory for mitigations.

References

https://github.com/grpc/grpc/pull/32309
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/37IDNVY5AWVH7JDMM2SDTL24ZPPZJNSY/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VWE44J5FG7THHL7XVEVTNIGEYBNKJBLL/
https://github.com/grpc/grpc/pull/32309
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/37IDNVY5AWVH7JDMM2SDTL24ZPPZJNSY/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VWE44J5FG7THHL7XVEVTNIGEYBNKJBLL/

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