What is CVE-2021-27098?

CVE-2021-27098 is a high-severity security vulnerability in github.com/spiffe/spire (go), affecting versions >= 0.8.1, < 0.8.5. It is fixed in 0.8.5, 0.9.4, 0.10.2, 0.11.3, 0.12.1.

How severe is CVE-2021-27098?

CVE-2021-27098 has a CVSS score of 8.1 (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 versions of github.com/spiffe/spire are affected by CVE-2021-27098?

github.com/spiffe/spire (go) versions >= 0.8.1, < 0.8.5 is affected.

Is there a fix for CVE-2021-27098?

Yes. CVE-2021-27098 is fixed in 0.8.5, 0.9.4, 0.10.2, 0.11.3, 0.12.1. Upgrade to this version or later.

Is CVE-2021-27098 exploitable, and should I be worried?

Whether CVE-2021-27098 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-2021-27098 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-2021-27098 in github.com/spiffe/spire

Q: How severe is CVE-2021-27098?

CVE-2021-27098 has a CVSS score of 8.1 (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 versions of github.com/spiffe/spire are affected by CVE-2021-27098?

github.com/spiffe/spire (go) versions >= 0.8.1, < 0.8.5 is affected.

Q: Is there a fix for CVE-2021-27098?

Yes. CVE-2021-27098 is fixed in 0.8.5, 0.9.4, 0.10.2, 0.11.3, 0.12.1. Upgrade to this version or later.

Q: Is CVE-2021-27098 exploitable, and should I be worried?

Whether CVE-2021-27098 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-2021-27098 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-2021-27098?

Upgrade: github.com/spiffe/spire to 0.8.5 or later, github.com/spiffe/spire to 0.9.4 or later, github.com/spiffe/spire to 0.10.2 or later, github.com/spiffe/spire to 0.11.3 or later, github.com/spiffe/spire to 0.12.1 or later.

Summary

Legacy Node API Allows Impersonation in github.com/spiffe/spire/pkg/server/endpoints/node

In SPIRE 0.8.1 through 0.8.4 and before versions 0.9.4, 0.10.2, 0.11.3 and 0.12.1, specially crafted requests to the FetchX509SVID RPC of SPIRE Server’s Legacy Node API (github.com/spiffe/spire/pkg/server/endpoints/node) can result in the possible issuance of an X.509 certificate with a URI SAN for a SPIFFE ID that the agent is not authorized to distribute. Proper controls are in place to require that the caller presents a valid agent certificate that is already authorized to issue at least one SPIFFE ID, and the requested SPIFFE ID belongs to the same trust domain, prior to being able to trigger this vulnerability. This issue has been fixed in SPIRE versions 0.8.5, 0.9.4, 0.10.2, 0.11.3 and 0.12.1.

What are the changes introduced by the patched versions?

The changes introduced to address this issue are related to enforcing that the FetchX509SVID RPC of SPIRE Server’s Legacy Node API only issues X.509 certificates with SPIFFE IDs that the agent is authorized to distribute.

The patched version also includes a back-ported change that improves the handling of file descriptors related to workload attestation in SPIRE Agent.

There are no changes in the expected behavior of SPIRE.

Should I upgrade SPIRE?

All SPIRE users running affected versions are advised to upgrade to the corresponding patched version.

Workarounds

No workarounds have been identified for this vulnerability.

Impact

CVE-2021-27098 has a CVSS score of 8.1 (High). The vector is network-reachable, low 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 (0.8.5, 0.9.4, 0.10.2, 0.11.3, 0.12.1); upgrading removes the vulnerable code path.

Affected versions

github.com/spiffe/spire (>= 0.8.1, < 0.8.5) github.com/spiffe/spire (>= 0.9.0, < 0.9.4) github.com/spiffe/spire (>= 0.10.0, < 0.10.2) github.com/spiffe/spire (>= 0.11.0, < 0.11.3) github.com/spiffe/spire (>= 0.12.0, < 0.12.1)

Security releases

github.com/spiffe/spire → 0.8.5 (go) github.com/spiffe/spire → 0.9.4 (go) github.com/spiffe/spire → 0.10.2 (go) github.com/spiffe/spire → 0.11.3 (go) github.com/spiffe/spire → 0.12.1 (go)

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.

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Remediation advice

Upgrade the following packages to resolve this vulnerability:

github.com/spiffe/spire to 0.8.5 or later; github.com/spiffe/spire to 0.9.4 or later; github.com/spiffe/spire to 0.10.2 or later; github.com/spiffe/spire to 0.11.3 or later; github.com/spiffe/spire to 0.12.1 or later

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

Frequently Asked Questions

What is CVE-2021-27098? CVE-2021-27098 is a high-severity security vulnerability in github.com/spiffe/spire (go), affecting versions >= 0.8.1, < 0.8.5. It is fixed in 0.8.5, 0.9.4, 0.10.2, 0.11.3, 0.12.1.
How severe is CVE-2021-27098? CVE-2021-27098 has a CVSS score of 8.1 (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 versions of github.com/spiffe/spire are affected by CVE-2021-27098? github.com/spiffe/spire (go) versions >= 0.8.1, < 0.8.5 is affected.
Is there a fix for CVE-2021-27098? Yes. CVE-2021-27098 is fixed in 0.8.5, 0.9.4, 0.10.2, 0.11.3, 0.12.1. Upgrade to this version or later.
Is CVE-2021-27098 exploitable, and should I be worried? Whether CVE-2021-27098 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-2021-27098 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-2021-27098?
- Upgrade github.com/spiffe/spire to 0.8.5 or later
- Upgrade github.com/spiffe/spire to 0.9.4 or later
- Upgrade github.com/spiffe/spire to 0.10.2 or later
- Upgrade github.com/spiffe/spire to 0.11.3 or later
- Upgrade github.com/spiffe/spire to 0.12.1 or later

Other vulnerabilities in github.com/spiffe/spire

CVE-IDSeverityPackage summary

GHSA-M7VP-HQWV-7M5XHighgithub.com/spiffe/spire: Unbounded memory usage on exposed HTTP/2 (non-gRPC) endpoints