CVE-2021-30476Public exploitNetwork attack vector

Authentication bypass via omitted GCE bound labels

Published Apr 22, 2021 · Updated Aug 3, 2024

Authentication restriction bypass in HashiCorp Terraform Vault Provider before 2.19.1 allows remote attackers to access Vault via GCP auth. The vault_gcp_auth_backend_role resource incorrectly mapped bound_labels from Terraform configuration to the Vault role-creation API, so the requested labels were silently omitted. Exposure requires a Terraform-created GCE-type role configured with bound_labels and an attacker who satisfies the remaining GCP authentication criteria; successful authentication grants the Vault token privileges assigned to that role.

CVSS severity9.8
Critical
EPSS probability1.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication restriction bypass in HashiCorp Terraform Vault Provider before 2.19.1 allows remote attackers to access Vault via GCP auth. The vault_gcp_auth_backend_role resource incorrectly mapped bound_labels from Terraform configuration to the Vault role-creation API, so the requested labels were silently omitted. Exposure requires a Terraform-created GCE-type role configured with bound_labels and an attacker who satisfies the remaining GCP authentication criteria; successful authentication grants the Vault token privileges assigned to that role.

The record

CVE
CVE-2021-30476
Published
Apr 22, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1078.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1078.004Valid Accounts: Cloud Accounts

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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