AWSCloudTrail - Privilege escalation via Lambda policy

Back


Id	8e01c41d-bd4c-4bbe-aed5-18592735052d
Rulename	AWSCloudTrail - Privilege escalation via Lambda policy
Description	Detects inline IAM policy updates that grant broad AWS Lambda permissions, including combinations that can link Lambda with other services such as DynamoDB. These permissions can provide execution control and support privilege escalation paths in the cloud environment.
Severity	Medium
Tactics	PrivilegeEscalation
Techniques	T1098.003
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%20Web%20Services/Analytic%20Rules/AWS_PrivilegeEscalationViaLambdaPolicy.yaml
Version	1.0.2
Arm template	8e01c41d-bd4c-4bbe-aed5-18592735052d.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 contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:InvokeFunction") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "lambda:Invoke*")) or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*" and Action contains "dynamodb:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:CreateEventSourceMapping" and Action contains "dynamodb:PutItem" and Action contains "dynamodb:CreateTable") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "dynamodb:Put*" and Action contains "dynamodb: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

YAML

entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
name: AWSCloudTrail - Privilege escalation via Lambda policy
kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_PrivilegeEscalationViaLambdaPolicy.yaml
triggerOperator: gt
status: Available
queryPeriod: 1d
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
tactics:
- PrivilegeEscalation
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 contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:InvokeFunction") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "lambda:Invoke*")) or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*" and Action contains "dynamodb:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:CreateEventSourceMapping" and Action contains "dynamodb:PutItem" and Action contains "dynamodb:CreateTable") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "dynamodb:Put*" and Action contains "dynamodb: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
description: |
  Detects inline IAM policy updates that grant broad AWS Lambda permissions, including combinations that can
  link Lambda with other services such as DynamoDB. These permissions can provide execution control and support
  privilege escalation paths in the cloud environment.
severity: Medium
id: 8e01c41d-bd4c-4bbe-aed5-18592735052d
customDetails:
  UserIdentityArn: UserIdentityArn
  EventName: EventName
  PolicyName: PolicyName
  RecipientAccountId: RecipientAccountId
triggerThreshold: 0
queryFrequency: 1d
alertDetailsOverride:
  alertDescriptionFormat: Detected {{EventName}} Event, updating inline Lambda escalation policy {{PolicyName}} in account {{RecipientAccountId}}.
  alertDisplayNameFormat: AWS Lambda privilege escalation policy update by {{AccountName}}
version: 1.0.2
relevantTechniques:
- T1098.003

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/8e01c41d-bd4c-4bbe-aed5-18592735052d')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/8e01c41d-bd4c-4bbe-aed5-18592735052d')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Detected {{EventName}} Event, updating inline Lambda escalation policy {{PolicyName}} in account {{RecipientAccountId}}.",
          "alertDisplayNameFormat": "AWS Lambda privilege escalation policy update by {{AccountName}}"
        },
        "alertRuleTemplateName": "8e01c41d-bd4c-4bbe-aed5-18592735052d",
        "customDetails": {
          "EventName": "EventName",
          "PolicyName": "PolicyName",
          "RecipientAccountId": "RecipientAccountId",
          "UserIdentityArn": "UserIdentityArn"
        },
        "description": "Detects inline IAM policy updates that grant broad AWS Lambda permissions, including combinations that can\nlink Lambda with other services such as DynamoDB. These permissions can provide execution control and support\nprivilege escalation paths in the cloud environment.\n",
        "displayName": "AWSCloudTrail - Privilege escalation via Lambda 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%20Web%20Services/Analytic%20Rules/AWS_PrivilegeEscalationViaLambdaPolicy.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 contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"lambda:*\") or ((Action contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"lambda:CreateFunction\" and Action contains \"lambda:InvokeFunction\") or ((Action contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"lambda:Create*\" and Action contains \"lambda:Invoke*\")) or ((Action contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"lambda:*\" and Action contains \"dynamodb:*\") or ((Action contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"lambda:CreateFunction\" and Action contains \"lambda:CreateEventSourceMapping\" and Action contains \"dynamodb:PutItem\" and Action contains \"dynamodb:CreateTable\") or ((Action contains \"iam:*\" or Action contains \"iam:PassRole\") and Action contains \"lambda:Create*\" and Action contains \"dynamodb:Put*\" and Action contains \"dynamodb: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",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1098.003"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1098"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}