aws-sqs-public-queue

An SQS queue with Principal:* granting sqs:SendMessage (no condition) is publicly writable; any unauthenticated sender can trigger bound Lambda consumers via messaging-chains.

derived aws emits ExposedToInternet

match

A conjunctive graph pattern. Variables (?x) bind node ids; every clause must hold.

where

emit

source type	`Queue`
target type	`AnonymousIdentity`
source	`<SQS queue node>`
target	`<AnonymousIdentity>`
conditions	`resource_policy`
state logic	ACTIVE when the queue policy has a statement granting sqs:SendMessage (or a wildcard that includes it) to Principal:* or Principal:{"AWS":"*"} with NO condition (or only non-restricting conditions such as an always-true Bool condition). CONDITIONAL(resource_policy) when a condition exists that the caller must satisfy (aws:SourceIp, aws:SourceVpc, etc.) — the queue is not fully public but is reachable from a constrained source. BLOCKED by an SCP that denies cross-account or public access.

source type

Queue

target type

AnonymousIdentity

source

<SQS queue node>

target

<AnonymousIdentity>

conditions

resource_policy

state logic

ACTIVE when the queue policy has a statement granting sqs:SendMessage (or a wildcard that includes it) to Principal:* or Principal:{"AWS":"*"} with NO condition (or only non-restricting conditions such as an always-true Bool condition). CONDITIONAL(resource_policy) when a condition exists that the caller must satisfy (aws:SourceIp, aws:SourceVpc, etc.) — the queue is not fully public but is reachable from a constrained source. BLOCKED by an SCP that denies cross-account or public access.

Narrative

SQS queue {queue.name} grants sqs:SendMessage to Principal:* with no restricting condition; any unauthenticated caller can publish messages, enabling the Phase-10 trigger chain for any Lambda consumer bound to this queue via messaging-chains.

Raw rule rules/derived/aws/sqs.yaml

id: aws-sqs-public-queue
emits: ExposedToInternet
description: An SQS queue with Principal:* granting sqs:SendMessage (no condition) is publicly writable;
  any unauthenticated sender can trigger bound Lambda consumers via messaging-chains.
match:
- match_record:
    resource_type: AWS::SQS::Queue
    field: Policy
  where:
  - statement grants sqs:SendMessage (or sqs:*) to Principal:* with no effective restricting condition
where:
- node_type(?queue) == Queue
emit:
  source_type: Queue
  target_type: AnonymousIdentity
  source: <SQS queue node>
  target: <AnonymousIdentity>
  permissions: []
  conditions:
  - resource_policy
  state_logic: "ACTIVE when the queue policy has a statement granting sqs:SendMessage (or a wildcard that\
    \ includes it) to Principal:* or Principal:{\"AWS\":\"*\"} with NO condition (or only non-restricting\
    \ conditions such as an always-true Bool condition). CONDITIONAL(resource_policy) when a condition\
    \ exists that the caller must satisfy (aws:SourceIp, aws:SourceVpc, etc.) \u2014 the queue is not\
    \ fully public but is reachable from a constrained source. BLOCKED by an SCP that denies cross-account\
    \ or public access."
  confidence: 0.98
  derived_from:
  - aws-sqs-public-send-policy (explicit)
  false_positive_note: "Principal:* WITH a meaningful condition (aws:SourceIp range, aws:SourceVpc, aws:PrincipalOrgID)\
    \ is NOT ExposedToInternet \u2014 it is conditionally reachable. Downgrade to CONDITIONAL(condition_expression)\
    \ when a non-trivial condition is present. aws:PrincipalOrgID restricts to the org \u2014 ExposedToTenant,\
    \ not ExposedToInternet. An sqs:ReceiveMessage-only wildcard grant does NOT make the queue a public\
    \ write target; check that the allowed action includes sqs:SendMessage. VPC endpoint policies (not\
    \ queue policies) do not appear in GetQueueAttributes[Policy] and are handled separately."
  narrative: SQS queue {queue.name} grants sqs:SendMessage to Principal:* with no restricting condition;
    any unauthenticated caller can publish messages, enabling the Phase-10 trigger chain for any Lambda
    consumer bound to this queue via messaging-chains.