GHSA-74j8-88mm-7496 CVE-2020-8561
Confused Deputy in Kubernetes
- Severity
- 4.1 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 2.10%
- Chance of exploitation in the next 30 days. Higher than 81.71% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-441 Unintended Proxy or Intermediary ('Confused Deputy')
- CWE-610 Externally Controlled Reference to a Resource in Another Sphere
- Fix
- None yet
- No fixed version published
Description
A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| k8s.io/kubernetes | <= 1.22.2 |
No fix yet |
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 3.1 4.1
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Weakness
CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')
The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product's control sphere. This causes the product to appear to be the source of the request, leading it to act as a proxy or other intermediary between the upstream component and the external actor.
How to prevent it
- Architecture and Design: Enforce the use of strong mutual authentication mechanism between the two parties.
- Architecture and Design: Whenever a product is an intermediary or proxy for transactions between two other components, the proxy core should not drop the identity of the initiator of the transaction. The immutability of the identity of the initiator must be maintained and should be forwarded all the way to the target.
CWE-610: Externally Controlled Reference to a Resource in Another Sphere
The product uses an externally controlled name or reference that resolves to a resource that is outside of the intended control sphere.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-r6j8-c6r2-37rr kube-controller-manager is vulnerable to half-blind Server Side Request Forgery through in-tree Portworx StorageClass | Medium | Also affects k8s.io/kubernetes |
| GHSA-4x4m-3c2p-qppc Kubernetes Nodes can delete themselves by adding an OwnerReference | Medium | Also affects k8s.io/kubernetes |
| GHSA-hj2p-8wj8-pfq4 kubernetes allows nodes to bypass dynamic resource allocation authorization checks | Low | Also affects k8s.io/kubernetes |
| GO-2025-3547 Kubernetes kube-apiserver Vulnerable to Race Condition | Low | Also affects k8s.io/kubernetes |
| GHSA-3wgm-2gw2-vh5m Kubernetes GitRepo Volume Inadvertent Local Repository Access | Medium | Also affects k8s.io/kubernetes |
| GHSA-vv39-3w5q-974q Kubernetes allows Command Injection affecting Windows nodes via nodes/*/logs/query API | Medium | Also affects k8s.io/kubernetes |
| GHSA-jgfp-53c3-624w Node Denial of Service via kubelet Checkpoint API | Medium | Also affects k8s.io/kubernetes |
| GHSA-27wf-5967-98gx Kubernetes kubelet arbitrary command execution | High | Also affects k8s.io/kubernetes |
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