Privilege escalation via CloudFormation policy

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Id	719d5204-10ab-4b1f-aee1-da7326750260
Rulename	Privilege escalation via CloudFormation policy
Description	Detected usage of AttachUserPolicy/AttachGroupPolicy/AttachRolePolicy on CloudFormation policy. Attackers could use these events for privilege escalation. Verify these actions with the user.
Severity	Medium
Tactics	PrivilegeEscalation
Techniques	T1484
Required data connectors	AWS
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_PrivilegeEscalationViaCloudFormationPolicy.yaml
Version	1.0.1
Arm template	719d5204-10ab-4b1f-aee1-da7326750260.json

KQL

AWSCloudTrail
  | where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | extend PolicyName = tostring(parse_json(RequestParameters).policyName)
  | extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
  | mvexpand Statement
  | extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
  | extend Action = tostring(Action)
  | where Effect =~ "Allow" and (((Action has "iam:*" or Action has "iam:PassRole") and Action has "cloudformation:*") or ((Action has "iam:*" or Action has "iam:PassRole") and Action contains "cloudformation:DescribeStacks" and Action contains "cloudformation:CreateStack") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "cloudformation:Describe*" and Action contains "cloudformation:Create*")) and Resource == "*" and Condition == ""
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
  | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName
  | extend timestamp = TimeGenerated

YAML

severity: Medium
relevantTechniques:
- T1484
queryFrequency: 1d
kind: Scheduled
version: 1.0.1
name: Privilege escalation via CloudFormation policy
triggerOperator: gt
description: |
    'Detected usage of AttachUserPolicy/AttachGroupPolicy/AttachRolePolicy on CloudFormation policy. Attackers could use these events for privilege escalation. Verify these actions with the user.'
queryPeriod: 1d
query: |
  AWSCloudTrail
    | where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
    | extend PolicyName = tostring(parse_json(RequestParameters).policyName)
    | extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
    | mvexpand Statement
    | extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
    | extend Action = tostring(Action)
    | where Effect =~ "Allow" and (((Action has "iam:*" or Action has "iam:PassRole") and Action has "cloudformation:*") or ((Action has "iam:*" or Action has "iam:PassRole") and Action contains "cloudformation:DescribeStacks" and Action contains "cloudformation:CreateStack") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "cloudformation:Describe*" and Action contains "cloudformation:Create*")) and Resource == "*" and Condition == ""
    | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
    | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
    | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
    | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
      AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
    | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName
    | extend timestamp = TimeGenerated  
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
- entityType: IP
  fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
tactics:
- PrivilegeEscalation
status: Available
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_PrivilegeEscalationViaCloudFormationPolicy.yaml
id: 719d5204-10ab-4b1f-aee1-da7326750260
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/719d5204-10ab-4b1f-aee1-da7326750260')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/719d5204-10ab-4b1f-aee1-da7326750260')]",
      "properties": {
        "alertRuleTemplateName": "719d5204-10ab-4b1f-aee1-da7326750260",
        "customDetails": null,
        "description": "'Detected usage of AttachUserPolicy/AttachGroupPolicy/AttachRolePolicy on CloudFormation policy. Attackers could use these events for privilege escalation. Verify these actions with the user.'\n",
        "displayName": "Privilege escalation via CloudFormation policy",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              },
              {
                "columnName": "RecipientAccountId",
                "identifier": "CloudAppAccountId"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_PrivilegeEscalationViaCloudFormationPolicy.yaml",
        "query": "AWSCloudTrail\n  | where EventName in (\"PutUserPolicy\",\"PutRolePolicy\",\"PutGroupPolicy\") and isempty(ErrorCode) and isempty(ErrorMessage)\n  | extend PolicyName = tostring(parse_json(RequestParameters).policyName)\n  | extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement\n  | mvexpand Statement\n  | extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)\n  | extend Action = tostring(Action)\n  | where Effect =~ \"Allow\" and (((Action has \"iam:*\" or Action has \"iam:PassRole\") and Action has \"cloudformation:*\") or ((Action has \"iam:*\" or Action has \"iam:PassRole\") and Action contains \"cloudformation:DescribeStacks\" and Action contains \"cloudformation:CreateStack\") or ((Action contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"cloudformation:Describe*\" and Action contains \"cloudformation:Create*\")) and Resource == \"*\" and Condition == \"\"\n  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)\n  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])\n  | extend AccountName = case( UserIdentityPrincipalid == \"Anonymous\", \"Anonymous\", isempty(UserIdentityUserName), UserName, UserIdentityUserName)\n  | extend AccountName = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 0)[0]), AccountName),\n    AccountUPNSuffix = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 1)[0]), \"\")\n  | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName\n  | extend timestamp = TimeGenerated\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1484"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}