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A mis-written Kubernetes NetworkPolicy in ctfer-io/monitoring versions before 0.2.1 fails to properly isolate components, violating the intended “security-by-default” model . This improper access control (CWE-284) allows an attacker who has compromised one part of the system to pivot laterally and communicate with any other namespace within the cluster . The flaw, which requires no authentication or user interaction, breaks namespace isolation and exposes sensitive telemetry data like logs and metrics to unauthorized actors . The vulnerability is fixed in version 0.2.1 by removing the flawed inter-ns NetworkPolicy .
DailyCVE Form:
Platform: ctfer-io monitoring
Version: < 0.2.1
Vulnerability : Improper Access Control
Severity: High
date: 2026-03-13
Prediction: March 2026 patch
What Undercode Say:
Analytics:
The vulnerability stems from a NetworkPolicy that was too permissive, effectively allowing traffic to flow across namespace boundaries. This misconfiguration bypasses the Kubernetes security model where namespaces are expected to provide environmental isolation. Successful exploitation allows an attacker to move laterally from a compromised pod in one namespace to access services and potentially steal secrets in another, vastly expanding the blast radius of an initial breach.
Bash Commands & Codes:
To identify if your cluster is using the vulnerable component and to apply the workaround, use the following commands.
1. Check for the vulnerable monitoring component:
kubectl get pods --all-namespaces | grep ctfer-io-monitoring
2. List the offending network policies (prefixed with inter-ns-):
kubectl get networkpolicy --all-namespaces | grep inter-ns-
3. Apply the workaround to delete all `inter-ns-` policies in monitoring namespaces:
for ns in $(kubectl get ns -o jsonpath='{.items[].metadata.name}' | tr ' ' '\n' | grep '^monitoring-'); do
kubectl -n "$ns" get networkpolicy -o name \
| grep '^networkpolicy.networking.k8s.io/inter-ns-' \
| xargs -r kubectl -n "$ns" delete
done
How Exploit:
An attacker first gains a foothold inside any pod within the cluster. From this compromised pod, they scan the internal network and discover services in other namespaces. Because the flawed `inter-ns-` NetworkPolicy allows cross-namespace traffic, the attacker can then directly connect to those services, such as internal databases, APIs, or monitoring backends, without any further authentication or network restrictions.
Protection from this CVE:
- Immediate Patch: Upgrade the `ctfer-io/monitoring` component to version 0.2.1 or later .
- Manual Workaround: If an immediate upgrade is not possible, delete the vulnerable `inter-ns-` NetworkPolicy from the monitoring namespaces using the bash script provided above .
- Long-term Prevention: Implement a “default deny” network policy for all namespaces to enforce the principle of least privilege, ensuring that only explicitly allowed traffic is permitted.
Impact:
Lateral Movement: An attacker can pivot from a single compromised pod to any other namespace in the cluster .
Data Breach: Unauthorized access to sensitive telemetry data (logs, metrics, traces) collected across the cluster .
Broken Isolation: Undermines the fundamental security boundary provided by Kubernetes namespaces, turning a minor compromise into a potential cluster-wide incident .
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Sources:
Reported By: github.com
Extra Source Hub:
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