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Detection rules › Kusto

Apache - Apache 2.4.49 flaw CVE-2021-41773

Status
available
Severity
high
Time window
10m
Source
github.com/Azure/Azure-Sentinel

'Detects using Apache 2.4.49 flaw CVE-2021-41773'

MITRE ATT&CK coverage

TacticTechniques
Initial Access
Lateral Movement

Rule body

id: 767f9dc4-3b01-11ec-8d3d-0242ac130003
name: Apache - Apache 2.4.49 flaw CVE-2021-41773 
description: |
  'Detects using Apache 2.4.49 flaw CVE-2021-41773'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    datatypes:
      - ApacheHTTPServer_CL
queryFrequency: 10m
queryPeriod: 10m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
  - LateralMovement
relevantTechniques:
  - T1190
  - T1133
  - T1210
query: |
  ApacheHTTPServer
  | where HttpRequestMethod =~ "GET"
  | where UrlOriginal has_all ("/cgi-bin/", "/%2e%2e/")
  | where HttpStatusCode == "200" 
  | extend UrlCustomEntity = UrlOriginal
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Stage 1: source

ApacheHTTPServer

Stage 2: where

| where HttpRequestMethod =~ "GET"

Stage 3: where

| where UrlOriginal has_all ("/cgi-bin/", "/%2e%2e/")

Stage 4: where

| where HttpStatusCode == "200"

Stage 5: extend

| extend UrlCustomEntity = UrlOriginal

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
HttpRequestMethodeq
  • GET
field:"HttpRequestMethod" kind:eq value:"GET"
HttpStatusCodeeq
  • 200
field:"HttpStatusCode" kind:eq value:"200"
UrlOriginalmatch
  • /%2e%2e/ transforms: term
  • /cgi-bin/ transforms: term
field:"UrlOriginal" kind:match

Output fields

These fields are emitted when the rule matches.

FieldSource
UrlCustomEntityextend