Detection rules › Kusto
Vulnerable Machines related to log4j CVE-2021-44228
'This query uses the Azure Defender Security Nested Recommendations data to find machines vulnerable to log4j CVE-2021-44228. Log4j is an open-source Apache logging library that is used in many Java-based applications. Security Nested Recommendations data is sent to Microsoft Sentinel using the continuous export feature of Azure Defender(refrence link below). Reference: https://msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44228-apache-log4j2/ Reference: https://docs.microsoft.com/azure/security-center/continuous-export?tabs=azure-portal Reference: https://techcommunity.microsoft.com/t5/microsoft-defender-for-cloud/how-defender-for-cloud-displays-machines-affected-by-log4j/ba-p/3037271'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | |
| Execution |
Rule body
id: 3d71fc38-f249-454e-8479-0a358382ef9a
name: Vulnerable Machines related to log4j CVE-2021-44228
description: |
'This query uses the Azure Defender Security Nested Recommendations data to find machines vulnerable to log4j CVE-2021-44228.
Log4j is an open-source Apache logging library that is used in many Java-based applications. Security Nested Recommendations data is sent to Microsoft Sentinel using the continuous export feature of Azure Defender(refrence link below).
Reference: https://msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44228-apache-log4j2/
Reference: https://docs.microsoft.com/azure/security-center/continuous-export?tabs=azure-portal
Reference: https://techcommunity.microsoft.com/t5/microsoft-defender-for-cloud/how-defender-for-cloud-displays-machines-affected-by-log4j/ba-p/3037271'
severity: High
status: Available
requiredDataConnectors: []
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
- Execution
relevantTechniques:
- T1190
- T1203
tags:
- Log4j
- CVE-2021-44228
- Log4shell
query: |
SecurityNestedRecommendation
| where RemediationDescription has 'CVE-2021-44228'
| parse ResourceDetails with * 'virtualMachines/' VirtualMachine '"' *
| summarize arg_min(TimeGenerated, *) by TenantId, RecommendationSubscriptionId, VirtualMachine, RecommendationName,Description,RemediationDescription, tostring(AdditionalData),VulnerabilityId
| extend Timestamp = TimeGenerated
entityMappings:
- entityType: Host
fieldMappings:
- identifier: HostName
columnName: VirtualMachine
version: 1.0.3
kind: Scheduled
Stages and Predicates
Stage 1: source
SecurityNestedRecommendation
Stage 2: where
| where RemediationDescription has 'CVE-2021-44228'
Stage 3: parse
| parse ResourceDetails with * 'virtualMachines/' VirtualMachine '"' *
Stage 4: summarize
| summarize arg_min(TimeGenerated, *) by TenantId, RecommendationSubscriptionId, VirtualMachine, RecommendationName,Description,RemediationDescription, tostring(AdditionalData),VulnerabilityId
Stage 5: extend
| extend Timestamp = TimeGenerated
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
RemediationDescription | match |
| field:"RemediationDescription" kind:match value:"CVE-2021-44228" |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
Description | summarize |
RecommendationName | summarize |
RecommendationSubscriptionId | summarize |
RemediationDescription | summarize |
TenantId | summarize |
VirtualMachine | summarize |
VulnerabilityId | summarize |
Timestamp | extend |