CVE-2019-9946

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-04-02 · updated 2026-06-17
Weakness: CWE-670

Description

Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4 has a network firewall misconfiguration which affects Kubernetes. The CNI 'portmap' plugin, used to setup HostPorts for CNI, inserts rules at the front of the iptables nat chains; which take precedence over the KUBE- SERVICES chain. Because of this, the HostPort/portmap rule could match incoming traffic even if there were better fitting, more specific service definition rules like NodePorts later in the chain. The issue is fixed in CNI 0.7.5 and Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0.

Affected products

Cncf Portmap: before 0.7.5 — fixed in 0.7.5
Kubernetes: before 1.11.9; from 1.12.0 before 1.12.7; from 1.13.0 before 1.13.5; 1.13.6-beta0, 1.14.0-alpha0, 1.14.0-alpha1, 1.14.0-alpha2, 1.14.0-alpha3, 1.14.0-beta0 (+3) — fixed in 1.11.9, 1.12.7, 1.13.5
NetApp Cloud Insights: all versions

How to fix

Upgrade to a fixed version: Cncf Portmap 0.7.5; Kubernetes 1.11.9, 1.12.7, 1.13.5. Check the vendor advisory for mitigations.

References

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