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Ingress NginxWeb server / proxy · Kubernetes

CVE-2021-25745

HIGH · 8.1 CVSS v3.1 Published 2022-05-06
Fix available
A fix is available. Upgrade to 1.2.0 or later.
See remediation →
87/100
Remediation priority · High
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
A security issue was discovered in ingress-nginx where a user that can create or update ingress objects can use the spec.rules[].http.paths[].path field of an Ingress object (in the networking.k8s.io or extensions API group) to obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.

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 · high confidence

A vulnerability in ingress-nginx allows users with permissions to create or update Ingress objects to manipulate the spec.rules[].http.paths[].path field to extract credentials from the ingress-nginx controller. In the default configuration, these credentials have cluster-wide access to all secrets, enabling lateral movement and complete cluster compromise.

MitigationLimit permissions on who can create/update Ingress objects and scope the ingress-nginx controller's service account permissions to only required namespaces until the upstream fix is applied.

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
Ingress NginxWeb server / proxy
Affected:< 1.2.0

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
None

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

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. Identify ingress-nginx version
    Run 'kubectl get pods -n ingress-nginx -o jsonpath="{.items[*].spec.containers[*].image}"' or check the deployment version with 'kubectl describe deployment ingress-nginx-controller -n ingress-nginx'
    Affected if The installed version is below 1.2.0
  2. Verify ingress-nginx namespace exists
    Run 'kubectl get namespace ingress-nginx' to confirm ingress-nginx is installed
    Affected if The namespace does not exist (ingress-nginx may not be in use)
  3. Check who can create or update Ingress objects
    Run 'kubectl auth can-i create ingresses --as=<user>' for relevant users, or inspect ClusterRole/Role bindings with 'kubectl get clusterrolebindings -o wide | grep -i ingress'
    Affected if Users or service accounts outside of cluster admins have create/update permissions on Ingress objects
  4. Review ingress-nginx controller service account permissions
    Run 'kubectl auth can-i get secrets --as=system:serviceaccount:ingress-nginx:ingress-nginx' and check ClusterRole bindings: 'kubectl get clusterrolebinding -o wide | grep ingress-nginx'
    Affected if The ingress-nginx service account has cluster-wide access to secrets (verbs include get/list/watch on all secrets across namespaces)

You are affected if ingress-nginx version is below 1.2.0 AND non-admin users can create/update Ingress objects AND the ingress-nginx controller service account has broad secret access permissions.

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 1.2.0 or later
Fixed in 1.2.0
Interim mitigation

Limit permissions on who can create/update Ingress objects and scope the ingress-nginx controller's service account permissions to only required namespaces until the upstream fix is applied.

Recommended fix High confidence

ingress-nginx controller version 1.2.0 or later

  1. Check the current version of ingress-nginx controller running in the cluster using: kubectl get pods -n ingress-nginx -o jsonpath='{.items[0].spec.containers[0].image}'
  2. Upgrade ingress-nginx controller to version 1.2.0 or later. For Helm-based installations, run: helm upgrade ingress-nginx ingress-nginx --ingress-class=nginx --repo=https://kubernetes.github.io/ingress-nginx --set controller.image.tag=v1.2.0
  3. Alternatively, for manifest-based installations, update the deployment YAML and apply: kubectl apply -f <updated-manifest>.yaml
  4. Verify the upgrade was successful by checking the controller pod is running and the version is correct: kubectl get pods -n ingress-nginx -l app.kubernetes.io/name=ingress-nginx
  5. Ensure the ingress-nginx controller has access only to necessary secrets by reviewing RBAC settings and controller configuration
Caveat Upgrading ingress-nginx may introduce changes in behavior or require updates to Ingress definitions; review the ingress-nginx changelog for any breaking changes between current and 1.2.0

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

Fix this in Ingress Nginx Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
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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-2021-25745 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data