Policy does not prevent use of root user Affecting Deployment service in Kubernetes
Severity Framework
CCSS (Common Configuration Scoring System) is a set of measures used to determine the severity of the rule.
Snyk CCSS
Rule category
Each rule is associated with a high-level category. For example IAM, Container, Monitoring, Logging, Network, etc.
IAM/ Privileged Access
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- Snyk IDSNYK-CC-00635
- creditSnyk Research Team
Description
The Pod Security Policy does not prevent the use of the root user. Running a container as the root user in Kubernetes increases the attack surface by granting the container more privileges than necessary.
How to fix?
Set runAsUser to MustRunAsNonRoot, or exclude UID 0 from MustRunAs range.
Set run_as_user to MustRunAsNonRoot, or exclude UID 0 from MustRunAs range.
Example Configuration
resource "kubernetes_pod_security_policy" "allowed" {
metadata {
name = "terraform-example"
}
spec {
privileged = false
allow_privilege_escalation = false
volumes = [
"configMap",
"emptyDir",
"projected",
"secret",
"downwardAPI",
"persistentVolumeClaim",
]
run_as_user {
rule = "MustRunAsNonRoot"
}
se_linux {
rule = "RunAsAny"
}
supplemental_groups {
rule = "MustRunAs"
range {
min = 1
max = 65535
}
}
fs_group {
rule = "MustRunAs"
range {
min = 1
max = 65535
}
}
read_only_root_filesystem = true
}
}
resource "kubernetes_pod_security_policy" "allowed2" {
metadata {
name = "terraform-example635"
}
spec {
privileged = false
allow_privilege_escalation = false
volumes = [
"configMap",
"emptyDir",
"projected",
"secret",
"downwardAPI",
"persistentVolumeClaim",
]
run_as_user {
rule = "MustRunAs"
range {
min = 1
max = 65535
}
}
se_linux {
rule = "RunAsAny"
}
supplemental_groups {
rule = "MustRunAs"
range {
min = 1
max = 65535
}
}
fs_group {
rule = "MustRunAs"
range {
min = 1
max = 65535
}
}
read_only_root_filesystem = true
}
}