Cross-Account Trust Demo

{
  "kind": "cloud-threat-model-report",
  "version": "1.1",
  "tool": {
    "name": "cloud-threat-modeler",
    "version": "0.1.0"
  },
  "title": "Cross-Account Trust Demo",
  "analyzed_file": "sample_aws_cross_account_trust_unconstrained_plan.json",
  "analyzed_path": "/home/fleet/cloud-threat-modeler/fixtures/sample_aws_cross_account_trust_unconstrained_plan.json",
  "summary": {
    "normalized_resources": 2,
    "unsupported_resources": 0,
    "trust_boundaries": 2,
    "active_findings": 2,
    "total_findings": 2,
    "suppressed_findings": 0,
    "baselined_findings": 0,
    "severity_counts": {
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      "medium": 2,
      "low": 0
    }
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    "total_findings": 2,
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    "suppressions_path": null,
    "baseline_path": null
  },
  "inventory": {
    "provider": "aws",
    "unsupported_resources": [],
    "metadata": {
      "primary_account_id": "111122223333",
      "supported_resource_types": [
        "aws_db_instance",
        "aws_iam_instance_profile",
        "aws_iam_policy",
        "aws_iam_role",
        "aws_iam_role_policy",
        "aws_iam_role_policy_attachment",
        "aws_instance",
        "aws_internet_gateway",
        "aws_kms_key",
        "aws_lambda_function",
        "aws_lambda_permission",
        "aws_lb",
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        "aws_route_table",
        "aws_route_table_association",
        "aws_s3_bucket",
        "aws_s3_bucket_policy",
        "aws_s3_bucket_public_access_block",
        "aws_secretsmanager_secret",
        "aws_secretsmanager_secret_policy",
        "aws_security_group",
        "aws_security_group_rule",
        "aws_sns_topic",
        "aws_sqs_queue",
        "aws_subnet",
        "aws_vpc"
      ]
    },
    "resources": [
      {
        "address": "aws_iam_role.deployer",
        "provider": "aws",
        "resource_type": "aws_iam_role",
        "name": "deployer",
        "category": "iam",
        "identifier": "release-deployer-role",
        "arn": "arn:aws:iam::111122223333:role/release-deployer-role",
        "vpc_id": null,
        "subnet_ids": [],
        "security_group_ids": [],
        "attached_role_arns": [],
        "network_rules": [],
        "policy_statements": [],
        "public_access_configured": false,
        "public_exposure": false,
        "data_sensitivity": "standard",
        "metadata": {
          "assume_role_policy": {
            "Version": "2012-10-17",
            "Statement": [
              {
                "Effect": "Allow",
                "Action": "sts:AssumeRole",
                "Principal": {
                  "Service": "lambda.amazonaws.com"
                }
              },
              {
                "Effect": "Allow",
                "Action": "sts:AssumeRole",
                "Principal": {
                  "AWS": "arn:aws:iam::444455556666:role/github-actions-deployer"
                }
              }
            ]
          },
          "trust_principals": [
            "arn:aws:iam::444455556666:role/github-actions-deployer",
            "lambda.amazonaws.com"
          ],
          "trust_statements": [
            {
              "principals": [
                "lambda.amazonaws.com"
              ],
              "narrowing_condition_keys": [],
              "narrowing_conditions": [],
              "has_narrowing_conditions": false
            },
            {
              "principals": [
                "arn:aws:iam::444455556666:role/github-actions-deployer"
              ],
              "narrowing_condition_keys": [],
              "narrowing_conditions": [],
              "has_narrowing_conditions": false
            }
          ],
          "inline_policy_names": [],
          "public_access_reasons": [],
          "public_exposure_reasons": [],
          "public_access_configured": false,
          "internet_ingress": false,
          "internet_ingress_capable": false,
          "internet_ingress_reasons": [],
          "public_subnet": false,
          "has_nat_gateway_egress": false,
          "direct_internet_reachable": false
        }
      },
      {
        "address": "aws_lambda_function.deployer",
        "provider": "aws",
        "resource_type": "aws_lambda_function",
        "name": "deployer",
        "category": "compute",
        "identifier": "release-deployer",
        "arn": "arn:aws:lambda:us-east-1:111122223333:function:release-deployer",
        "vpc_id": null,
        "subnet_ids": [],
        "security_group_ids": [],
        "attached_role_arns": [
          "arn:aws:iam::111122223333:role/release-deployer-role"
        ],
        "network_rules": [],
        "policy_statements": [],
        "public_access_configured": false,
        "public_exposure": false,
        "data_sensitivity": "standard",
        "metadata": {
          "runtime": "python3.12",
          "handler": "handler.main",
          "vpc_enabled": false,
          "public_access_reasons": [],
          "public_exposure_reasons": [],
          "public_access_configured": false,
          "internet_ingress": false,
          "internet_ingress_capable": false,
          "internet_ingress_reasons": [],
          "public_subnet": false,
          "has_nat_gateway_egress": false,
          "direct_internet_reachable": false
        }
      }
    ]
  },
  "trust_boundaries": [
    {
      "identifier": "admin-to-workload-plane:aws_iam_role.deployer->aws_lambda_function.deployer",
      "boundary_type": "admin-to-workload-plane",
      "source": "aws_iam_role.deployer",
      "target": "aws_lambda_function.deployer",
      "description": "aws_iam_role.deployer governs actions performed by aws_lambda_function.deployer.",
      "rationale": "IAM configuration acts as a control-plane boundary because the workload inherits whatever privileges the role carries."
    },
    {
      "identifier": "cross-account-or-role-access:arn:aws:iam::444455556666:role/github-actions-deployer->aws_iam_role.deployer",
      "boundary_type": "cross-account-or-role-access",
      "source": "arn:aws:iam::444455556666:role/github-actions-deployer",
      "target": "aws_iam_role.deployer",
      "description": "aws_iam_role.deployer trusts arn:aws:iam::444455556666:role/github-actions-deployer.",
      "rationale": "A foreign AWS account can cross into this role's trust boundary."
    }
  ],
  "findings": [
    {
      "fingerprint": "sha256:60299a231fe096b74b8babb729e994789afdee7376e066dedeae2ea15198e399",
      "title": "Cross-account or broad role trust lacks narrowing conditions",
      "rule_id": "aws-role-trust-missing-narrowing",
      "category": "Elevation of Privilege",
      "severity": "medium",
      "affected_resources": [
        "aws_iam_role.deployer"
      ],
      "trust_boundary_id": "cross-account-or-role-access:arn:aws:iam::444455556666:role/github-actions-deployer->aws_iam_role.deployer",
      "rationale": "aws_iam_role.deployer trusts arn:aws:iam::444455556666:role/github-actions-deployer without supported narrowing conditions such as `sts:ExternalId`, `aws:SourceArn`, or `aws:SourceAccount`. That leaves the assume-role path dependent on a broad or external principal match alone.",
      "recommended_mitigation": "Keep the trusted principal as specific as possible and add supported assume-role conditions such as `ExternalId`, `SourceArn`, or `SourceAccount` when crossing accounts or trusting broad principals.",
      "evidence": [
        {
          "key": "trust_principals",
          "values": [
            "arn:aws:iam::444455556666:role/github-actions-deployer"
          ]
        },
        {
          "key": "trust_scope",
          "values": [
            "principal belongs to foreign account 444455556666"
          ]
        },
        {
          "key": "trust_narrowing",
          "values": [
            "supported narrowing conditions present: false",
            "supported narrowing condition keys: none"
          ]
        }
      ],
      "severity_reasoning": {
        "internet_exposure": 0,
        "privilege_breadth": 1,
        "data_sensitivity": 0,
        "lateral_movement": 1,
        "blast_radius": 2,
        "final_score": 4,
        "severity": "medium",
        "computed_severity": null
      }
    },
    {
      "fingerprint": "sha256:3c81458a2802d71611ccf7a1c27a31662a31f0698aa3d7bf1583f1c85d6896fd",
      "title": "Role trust relationship expands blast radius",
      "rule_id": "aws-role-trust-expansion",
      "category": "Elevation of Privilege",
      "severity": "medium",
      "affected_resources": [
        "aws_iam_role.deployer"
      ],
      "trust_boundary_id": "cross-account-or-role-access:arn:aws:iam::444455556666:role/github-actions-deployer->aws_iam_role.deployer",
      "rationale": "aws_iam_role.deployer can be assumed by arn:aws:iam::444455556666:role/github-actions-deployer. Broad or foreign-account trust relationships increase the chance that compromise in one identity domain spills into another.",
      "recommended_mitigation": "Limit trust policies to the exact service principals or roles required, prefer role ARNs over account root where possible, and add conditions such as `ExternalId` or source ARN checks.",
      "evidence": [
        {
          "key": "trust_principals",
          "values": [
            "arn:aws:iam::444455556666:role/github-actions-deployer"
          ]
        },
        {
          "key": "trust_path",
          "values": [
            "trust principal belongs to foreign account 444455556666"
          ]
        }
      ],
      "severity_reasoning": {
        "internet_exposure": 0,
        "privilege_breadth": 1,
        "data_sensitivity": 0,
        "lateral_movement": 2,
        "blast_radius": 2,
        "final_score": 5,
        "severity": "medium",
        "computed_severity": null
      }
    }
  ],
  "suppressed_findings": [],
  "baselined_findings": [],
  "observations": [],
  "limitations": [
    "AWS support is intentionally limited to a curated v1 resource set rather than the full Terraform AWS provider.",
    "Subnet public/private classification prefers explicit route table associations and NAT or internet routes when present, but it does not model main-route-table inheritance or every routing edge case.",
    "IAM analysis resolves inline role policies, customer-managed role-policy attachments, and EC2 instance profiles present in the plan, but it does not expand AWS-managed policy documents that are not materialized in Terraform state.",
    "Resource-policy analysis focuses on explicit policy documents and Lambda permission resources present in the plan; it does not model every service-specific condition key or every downstream runtime authorization path.",
    "The engine reasons over Terraform planned values only and does not validate runtime drift, CloudTrail evidence, or post-deploy control-plane activity."
  ]
}

# Cross-Account Trust Demo

- Analyzed file: `sample_aws_cross_account_trust_unconstrained_plan.json`
- Provider: `aws`
- Normalized resources: `2`
- Unsupported resources: `0`

## Summary

This run identified **2 trust boundaries** and **2 findings** across **2 normalized resources**.

- High severity findings: `0`
- Medium severity findings: `2`
- Low severity findings: `0`

## Discovered Trust Boundaries

### `admin-to-workload-plane`

- Source: `aws_iam_role.deployer`
- Target: `aws_lambda_function.deployer`
- Description: aws_iam_role.deployer governs actions performed by aws_lambda_function.deployer.
- Rationale: IAM configuration acts as a control-plane boundary because the workload inherits whatever privileges the role carries.

### `cross-account-or-role-access`

- Source: `arn:aws:iam::444455556666:role/github-actions-deployer`
- Target: `aws_iam_role.deployer`
- Description: aws_iam_role.deployer trusts arn:aws:iam::444455556666:role/github-actions-deployer.
- Rationale: A foreign AWS account can cross into this role's trust boundary.

## Findings

### High

No findings in this severity band.

### Medium

#### Cross-account or broad role trust lacks narrowing conditions

- STRIDE category: Elevation of Privilege
- Affected resources: `aws_iam_role.deployer`
- Trust boundary: `cross-account-or-role-access:arn:aws:iam::444455556666:role/github-actions-deployer->aws_iam_role.deployer`
- Severity reasoning: internet_exposure +0, privilege_breadth +1, data_sensitivity +0, lateral_movement +1, blast_radius +2, final_score 4 => medium
- Rationale: aws_iam_role.deployer trusts arn:aws:iam::444455556666:role/github-actions-deployer without supported narrowing conditions such as `sts:ExternalId`, `aws:SourceArn`, or `aws:SourceAccount`. That leaves the assume-role path dependent on a broad or external principal match alone.
- Recommended mitigation: Keep the trusted principal as specific as possible and add supported assume-role conditions such as `ExternalId`, `SourceArn`, or `SourceAccount` when crossing accounts or trusting broad principals.
- Evidence:
  - trust principals: arn:aws:iam::444455556666:role/github-actions-deployer
  - trust scope: principal belongs to foreign account 444455556666
  - trust narrowing: supported narrowing conditions present: false; supported narrowing condition keys: none

#### Role trust relationship expands blast radius

- STRIDE category: Elevation of Privilege
- Affected resources: `aws_iam_role.deployer`
- Trust boundary: `cross-account-or-role-access:arn:aws:iam::444455556666:role/github-actions-deployer->aws_iam_role.deployer`
- Severity reasoning: internet_exposure +0, privilege_breadth +1, data_sensitivity +0, lateral_movement +2, blast_radius +2, final_score 5 => medium
- Rationale: aws_iam_role.deployer can be assumed by arn:aws:iam::444455556666:role/github-actions-deployer. Broad or foreign-account trust relationships increase the chance that compromise in one identity domain spills into another.
- Recommended mitigation: Limit trust policies to the exact service principals or roles required, prefer role ARNs over account root where possible, and add conditions such as `ExternalId` or source ARN checks.
- Evidence:
  - trust principals: arn:aws:iam::444455556666:role/github-actions-deployer
  - trust path: trust principal belongs to foreign account 444455556666

### Low

No findings in this severity band.

## Limitations / Unsupported Resources

- AWS support is intentionally limited to a curated v1 resource set rather than the full Terraform AWS provider.
- Subnet public/private classification prefers explicit route table associations and NAT or internet routes when present, but it does not model main-route-table inheritance or every routing edge case.
- IAM analysis resolves inline role policies, customer-managed role-policy attachments, and EC2 instance profiles present in the plan, but it does not expand AWS-managed policy documents that are not materialized in Terraform state.
- Resource-policy analysis focuses on explicit policy documents and Lambda permission resources present in the plan; it does not model every service-specific condition key or every downstream runtime authorization path.
- The engine reasons over Terraform planned values only and does not validate runtime drift, CloudTrail evidence, or post-deploy control-plane activity.