description: Versions < 1.5 of the Kubernetes ingress default backend, which handles invalid ingress traffic, exposed prometheus metrics publicly.
problem types: CWE-215 Information Exposure Through Debug Information
affected:
{
product: k8s.gcr.io/defaultbackend
vendor: Kubernetes
versions:
lessThan: 1.5, status: affected, version: defaultbackend, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5.3
baseSeverity: MEDIUM
confidentialityImpact: LOW
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
version: 3.1
]
workarounds: Mask the /metrics endpoint with an Ingress rule so that metrics aren't exposed publicly. See https://github.com/kubernetes/ingress-nginx/issues/1733#issuecomment-358492359