What is CVE-2023-32731?

CVE-2023-32731 is a high-severity security vulnerability in io.grpc:grpc-protobuf (maven), affecting versions >= 1.53.0, < 1.53.1. It is fixed in 1.53.1, 1.54.2.

How severe is CVE-2023-32731?

CVE-2023-32731 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which packages are affected by CVE-2023-32731?

io.grpc:grpc-protobuf (maven) versions >= 1.53.0, = 1.53.0, = 1.53.0, < 1.53.1.

Is there a fix for CVE-2023-32731?

Yes. CVE-2023-32731 is fixed in 1.53.1, 1.54.2. Upgrade to this version or later.

Is CVE-2023-32731 exploitable, and should I be worried?

Whether CVE-2023-32731 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2023-32731 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2023-32731 in io.grpc:grpc-protobuf | Intelligent Application Security

Q: How severe is CVE-2023-32731?

CVE-2023-32731 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which packages are affected by CVE-2023-32731?

io.grpc:grpc-protobuf (maven) versions >= 1.53.0, = 1.53.0, = 1.53.0, < 1.53.1.

Q: Is there a fix for CVE-2023-32731?

Yes. CVE-2023-32731 is fixed in 1.53.1, 1.54.2. Upgrade to this version or later.

Q: Is CVE-2023-32731 exploitable, and should I be worried?

Whether CVE-2023-32731 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2023-32731 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2023-32731?

Upgrade: io.grpc:grpc-protobuf to 1.53.1 or later, grpcio to 1.53.1 or later, grpc to 1.53.1 or later, grpcio to 1.54.2 or later, grpc to 1.54.2 or later, io.grpc:grpc-protobuf to 1.54.2 or later.

Summary

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.

Impact

CVE-2023-32731 has a CVSS score of 7.4 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.53.1, 1.54.2); upgrading removes the vulnerable code path.

Affected versions

io.grpc:grpc-protobuf (>= 1.53.0, < 1.53.1) grpcio (>= 1.53.0, < 1.53.1) grpc (>= 1.53.0, < 1.53.1) grpcio (>= 1.54.0, < 1.54.2) grpc (>= 1.54.0, < 1.54.2) io.grpc:grpc-protobuf (>= 1.54.0, < 1.54.2)

Security releases

io.grpc:grpc-protobuf → 1.53.1 (maven) grpcio → 1.53.1 (pip) grpc → 1.53.1 (rubygems) grpcio → 1.54.2 (pip) grpc → 1.54.2 (rubygems) io.grpc:grpc-protobuf → 1.54.2 (maven)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

See it in your environment

Remediation advice

Upgrade the following packages to resolve this vulnerability:

io.grpc:grpc-protobuf to 1.53.1 or later; grpcio to 1.53.1 or later; grpc to 1.53.1 or later; grpcio to 1.54.2 or later; grpc to 1.54.2 or later; io.grpc:grpc-protobuf to 1.54.2 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2023-32731? CVE-2023-32731 is a high-severity security vulnerability in io.grpc:grpc-protobuf (maven), affecting versions >= 1.53.0, < 1.53.1. It is fixed in 1.53.1, 1.54.2.
How severe is CVE-2023-32731? CVE-2023-32731 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which packages are affected by CVE-2023-32731?
- io.grpc:grpc-protobuf (maven) (versions >= 1.53.0, < 1.53.1)
- grpcio (pip) (versions >= 1.53.0, < 1.53.1)
- grpc (rubygems) (versions >= 1.53.0, < 1.53.1)
Is there a fix for CVE-2023-32731? Yes. CVE-2023-32731 is fixed in 1.53.1, 1.54.2. Upgrade to this version or later.
Is CVE-2023-32731 exploitable, and should I be worried? Whether CVE-2023-32731 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2023-32731 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2023-32731?
- Upgrade io.grpc:grpc-protobuf to 1.53.1 or later
- Upgrade grpcio to 1.53.1 or later
- Upgrade grpc to 1.53.1 or later
- Upgrade grpcio to 1.54.2 or later
- Upgrade grpc to 1.54.2 or later
- Upgrade io.grpc:grpc-protobuf to 1.54.2 or later

Other vulnerabilities in io.grpc:grpc-protobuf

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