S3 bucket exposed via ACL
Id | 6b9b4ee6-f4c1-4b86-8c8c-beb0bb59ae44 |
Rulename | S3 bucket exposed via ACL |
Description | Detected S3 bucket publicly exposed via ACL, which could lead for sensitive information leakage to the public. Verify the S3 object configurations. |
Severity | Medium |
Tactics | Exfiltration |
Techniques | T1537 |
Required data connectors | AWS |
Kind | Scheduled |
Query frequency | 1h |
Query period | 1h |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_S3BucketExposedviaACL.yaml |
Version | 1.0.0 |
Arm template | 6b9b4ee6-f4c1-4b86-8c8c-beb0bb59ae44.json |
AWSCloudTrail
| where EventName == "PutBucketAcl" and isempty(ErrorCode) and isempty(ErrorMessage)
| extend Grant = parse_json(tostring((parse_json(RequestParameters).AccessControlPolicy))).AccessControlList.Grant
| mvexpand Grant
| extend cannedacl = parse_json(tostring((parse_json(RequestParameters))))
| extend URI = parse_json(Grant).Grantee.URI, type = parse_json(Grant).Grantee.["xsi:type"], xamzacl = parse_json(cannedacl).["x-amz-acl"]
| where (type == "Group" and (URI endswith "AllUsers" or URI endswith "AuthenticatedUsers"))
or xamzacl in ("authenticated-read","public-read","public-read-write")
| extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]))
| extend timestamp = TimeGenerated, IPCustomEntity = SourceIpAddress, AccountCustomEntity = UserIdentityUserName
queryPeriod: 1h
version: 1.0.0
relevantTechniques:
- T1537
queryFrequency: 1h
kind: Scheduled
name: S3 bucket exposed via ACL
id: 6b9b4ee6-f4c1-4b86-8c8c-beb0bb59ae44
entityMappings:
- fieldMappings:
- columnName: AccountCustomEntity
identifier: FullName
entityType: Account
- fieldMappings:
- columnName: IPCustomEntity
identifier: Address
entityType: IP
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_S3BucketExposedviaACL.yaml
severity: Medium
query: |
AWSCloudTrail
| where EventName == "PutBucketAcl" and isempty(ErrorCode) and isempty(ErrorMessage)
| extend Grant = parse_json(tostring((parse_json(RequestParameters).AccessControlPolicy))).AccessControlList.Grant
| mvexpand Grant
| extend cannedacl = parse_json(tostring((parse_json(RequestParameters))))
| extend URI = parse_json(Grant).Grantee.URI, type = parse_json(Grant).Grantee.["xsi:type"], xamzacl = parse_json(cannedacl).["x-amz-acl"]
| where (type == "Group" and (URI endswith "AllUsers" or URI endswith "AuthenticatedUsers"))
or xamzacl in ("authenticated-read","public-read","public-read-write")
| extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]))
| extend timestamp = TimeGenerated, IPCustomEntity = SourceIpAddress, AccountCustomEntity = UserIdentityUserName
tactics:
- Exfiltration
description: |
'Detected S3 bucket publicly exposed via ACL, which could lead for sensitive information leakage to the public. Verify the S3 object configurations.'
requiredDataConnectors:
- connectorId: AWS
dataTypes:
- AWSCloudTrail
status: Available
triggerThreshold: 0
triggerOperator: gt
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/6b9b4ee6-f4c1-4b86-8c8c-beb0bb59ae44')]",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/6b9b4ee6-f4c1-4b86-8c8c-beb0bb59ae44')]",
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
"kind": "Scheduled",
"apiVersion": "2022-11-01",
"properties": {
"displayName": "S3 bucket exposed via ACL",
"description": "'Detected S3 bucket publicly exposed via ACL, which could lead for sensitive information leakage to the public. Verify the S3 object configurations.'\n",
"severity": "Medium",
"enabled": true,
"query": "AWSCloudTrail\n| where EventName == \"PutBucketAcl\" and isempty(ErrorCode) and isempty(ErrorMessage)\n| extend Grant = parse_json(tostring((parse_json(RequestParameters).AccessControlPolicy))).AccessControlList.Grant\n| mvexpand Grant\n| extend cannedacl = parse_json(tostring((parse_json(RequestParameters))))\n| extend URI = parse_json(Grant).Grantee.URI, type = parse_json(Grant).Grantee.[\"xsi:type\"], xamzacl = parse_json(cannedacl).[\"x-amz-acl\"]\n| where (type == \"Group\" and (URI endswith \"AllUsers\" or URI endswith \"AuthenticatedUsers\"))\n or xamzacl in (\"authenticated-read\",\"public-read\",\"public-read-write\")\n| extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]))\n| extend timestamp = TimeGenerated, IPCustomEntity = SourceIpAddress, AccountCustomEntity = UserIdentityUserName\n",
"queryFrequency": "PT1H",
"queryPeriod": "PT1H",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0,
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Exfiltration"
],
"techniques": [
"T1537"
],
"alertRuleTemplateName": "6b9b4ee6-f4c1-4b86-8c8c-beb0bb59ae44",
"customDetails": null,
"entityMappings": [
{
"fieldMappings": [
{
"identifier": "FullName",
"columnName": "AccountCustomEntity"
}
],
"entityType": "Account"
},
{
"fieldMappings": [
{
"identifier": "Address",
"columnName": "IPCustomEntity"
}
],
"entityType": "IP"
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_S3BucketExposedviaACL.yaml",
"status": "Available",
"templateVersion": "1.0.0"
}
}
]
}