CVE-2023-32732: gRPC connection termination issue in Grpc.Core
Summary
CVE-2023-32732: gRPC connection termination issue. Affects Grpc.Core versions < 2.52.0. Fixed in 2.52.0. How to fix ↓
Also tracked for
- grpcio · PyPI
- io.grpc:grpc-protobuf · Maven
- io.grpc:grpc-protobuf · Maven
- grpc · Debian:11
The same CVE-2023-32732 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
Grpc.Core is a NuGet package that provides the core functionality for gRPC, a high-performance, open-source framework for building distributed applications. It allows developers to define services using Protocol Buffers and enables efficient communication between clients and servers. However, a vulnerability has been discovered in Grpc.Core that can lead to the termination of connections between HTTP2 proxies and gRPC servers.
Vulnerability Detail
The vulnerability in Grpc.Core arises from a base64 encoding error for -bin suffixed headers. This error can be exploited by a client to cause a disconnection by the gRPC server. While HTTP2 proxies typically allow this type of encoding error, gRPC servers consider it an invalid request and terminate the connection. This vulnerability can potentially be abused by malicious clients to disrupt the communication between HTTP2 proxies and gRPC servers, leading to service interruptions or denial of service.
How To Fix
Latest published version: 2.46.6 as of 23 Oct 2026
Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
2.52.0
This is the first release that contains the fix.
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Workaround
No workaround has been provided for this vulnerability. It is essential to apply the recommended fix by upgrading to the fixed version of Grpc.Core.
Conclusion
In conclusion, the gRPC connection termination issue in Grpc.Core can be exploited by malicious clients to disrupt the communication between HTTP2 proxies and gRPC servers. To mitigate this vulnerability, it is crucial to upgrade Grpc.Core to version 2.52.0 or above. For further support on vulnerability remediation, you can contact DevNack.com.
See every vulnerability recorded for Grpc.Core →
FAQ
gRPC is an open-source framework that allows developers to define services using Protocol Buffers and enables efficient communication between clients and servers.
This vulnerability can be exploited by malicious clients to cause a termination of connections between HTTP2 proxies and gRPC servers, leading to service interruptions or denial of service.
To fix this vulnerability, you need to upgrade Grpc.Core to version 2.52.0 or above.
No workaround has been provided for this vulnerability. It is crucial to apply the recommended fix by upgrading to the fixed version of Grpc.Core.
You can find more information about this vulnerability in the GitHub Advisory Database: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/07/GHSA-9hxf-ppjv-w6rq/GHSA-9hxf-ppjv-w6rq.json
References
Related vulnerabilities
Recent vulnerabilities recorded for Grpc.Core.
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