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IstioApplication

CVE-2021-34824

HIGH · 8.8 CVSS v3.1 Published 2021-06-29
Fix available
A fix is available. Upgrade to 1.9.6 / 1.10.2 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Istio (1.8.x, 1.9.0-1.9.5 and 1.10.0-1.10.1) contains a remotely exploitable vulnerability where credentials specified in the Gateway and DestinationRule credentialName field can be accessed from different namespaces.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

In Istio, the Gateway and DestinationRule resources support a credentialName field for referencing TLS/certificate credentials. This vulnerability allows these credentials to be accessed across namespace boundaries - a resource in namespace A can reference secrets in namespace B when it should not have access. This violates namespace isolation and could allow unauthorized credential disclosure.

MitigationUpgrade Istio to a patched version (1.9.6+, 1.10.2+, or 1.11+) and audit all Gateway and DestinationRule resources to ensure credentialName references do not cross namespace boundaries inappropriately.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
IstioApplication
Affected:>= 1.8.0, < 1.9.6>= 1.10.0, < 1.10.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Istio control plane version
    Run 'istioctl version' or 'kubectl get pods -n istio-system -o jsonpath="{.items[*].spec.containers[*].image}"' to retrieve the installed Istio version
    Affected if The installed version falls within 1.8.0 to 1.9.5, or 1.10.0 to 1.10.1 (use semver comparison)
  2. Identify Gateway resources with credentialName
    Run 'kubectl get gateways -A -o json' and search for any Gateway resources that contain a 'credentialName' field in their spec or tls section
    Affected if Any Gateway resource has a credentialName field defined pointing to a secret
  3. Identify DestinationRule resources with credentialName
    Run 'kubectl get destinationrules -A -o json' and search for any DestinationRule resources that contain a 'credentialName' field in their spec or tls section
    Affected if Any DestinationRule resource has a credentialName field defined pointing to a secret
  4. Check for cross-namespace credential references
    For each resource found with credentialName, compare the namespace of the Gateway/DestinationRule (metadata.namespace) against the namespace where the referenced secret actually resides (verify with 'kubectl get secret <credentialName> -n <secret-namespace>')
    Affected if Any credentialName references a secret in a different namespace than the resource itself, indicating potential unauthorized cross-namespace access

You are affected if your Istio version is between 1.8.0-1.9.5 or 1.10.0-1.10.1 AND you have any Gateway or DestinationRule resources using credentialName to reference secrets in a different namespace.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.9.6 / 1.10.2 or later
Fixed in 1.9.61.10.2
Interim mitigation

Upgrade Istio to a patched version (1.9.6+, 1.10.2+, or 1.11+) and audit all Gateway and DestinationRule resources to ensure credentialName references do not cross namespace boundaries inappropriately.

Recommended fix High confidence

Istio 1.9.6, 1.10.2, or latest stable release (1.11+)

  1. Identify your current Istio version using 'istioctl version' or checking the deployment
  2. For Istio 1.8.x: upgrade to Istio 1.9.6 or later (preferably 1.10.2 or latest stable)
  3. For Istio 1.9.0-1.9.5: upgrade to Istio 1.9.6 or later (preferably latest stable)
  4. For Istio 1.10.0-1.10.1: upgrade to Istio 1.10.2 or later (preferably latest stable)
  5. Use 'istioctl upgrade' command or your Kubernetes manifest management tool to apply the upgrade
  6. After upgrade, verify the Istio control plane is healthy using 'istioctl verify-install'
  7. Test that Gateway and DestinationRule resources function correctly with the credentialName field
Caveat Review Istio release notes for your target version; minor version upgrades typically have minimal breaking changes but always test in non-production first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Istio Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-34824 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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