aws-msk-update-cluster-config

kafka:UpdateClusterConfiguration applies a new Kafka broker configuration version to the MSK cluster, affecting settings such as auto.create.topics.enable, log retention, and replication factors.

derived aws emits CanModifyConfiguration

match (effective permission)

{ "action": "kafka:UpdateClusterConfiguration", "resource_type": "AWS::MSK::Cluster" }

emit

source typeIdentity
target typeGenericMessaging
source<principal>
target<MSK Cluster (GenericMessaging)>
permissionskafka:UpdateClusterConfiguration
conditionsiam_permission
state logicACTIVE when the principal has effective kafka:UpdateClusterConfiguration on the cluster ARN. This modifies broker-level Kafka settings. Analyst note: enabling auto.create.topics.enable is particularly significant — it allows producers to create new topics implicitly, broadening the WriteData attack surface without explicit kafka-cluster:CreateTopic permission. BLOCKED by SCP or boundary denial.

Narrative

{principal.name} can apply a new Kafka broker configuration to cluster {target.name} (kafka:UpdateClusterConfiguration), altering settings such as auto.create.topics.enable, retention policies, and replication factors - changes that can expand the cluster's data-plane attack surface.

Raw rule rules/derived/aws/msk.yaml

id: aws-msk-update-cluster-config
emits: CanModifyConfiguration
description: kafka:UpdateClusterConfiguration applies a new Kafka broker configuration version to the
  MSK cluster, affecting settings such as auto.create.topics.enable, log retention, and replication factors.
match_effective_permission:
  action: kafka:UpdateClusterConfiguration
  resource_type: AWS::MSK::Cluster
emit:
  source_type: Identity
  target_type: GenericMessaging
  source: <principal>
  target: <MSK Cluster (GenericMessaging)>
  permissions:
  - kafka:UpdateClusterConfiguration
  conditions:
  - iam_permission
  state_logic: "ACTIVE when the principal has effective kafka:UpdateClusterConfiguration on the cluster\
    \ ARN. This modifies broker-level Kafka settings. Analyst note: enabling auto.create.topics.enable\
    \ is particularly significant \u2014 it allows producers to create new topics implicitly, broadening\
    \ the WriteData attack surface without explicit kafka-cluster:CreateTopic permission. BLOCKED by SCP\
    \ or boundary denial."
  derived_from:
  - effective kafka:UpdateClusterConfiguration on cluster ARN
  false_positive_note: "Cluster configuration changes require a rolling broker restart (MSK handles this\
    \ automatically), which temporarily disrupts broker availability. The security consequence of the\
    \ configuration change (e.g. enabling auto topic creation) is gradual \u2014 it takes effect after\
    \ the rolling restart completes. Not a real-time escalation but a persistent configuration modification."
  narrative: "{principal.name} can apply a new Kafka broker configuration to cluster {target.name} (kafka:UpdateClusterConfiguration),\
    \ altering settings such as auto.create.topics.enable, retention policies, and replication factors\
    \ \u2014 changes that can expand the cluster's data-plane attack surface."
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