CVE-2023-22518 Exploitation Attempt - Suspicious Confluence Child Process (Windows)

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Andreas Braathen (mnemonic.io)
Source: github.com/SigmaHQ/sigma

Detects exploitation attempt of CVE-2023-22518 (Confluence Data Center / Confluence Server), where an attacker can exploit vulnerable endpoints to e.g. create admin accounts and execute arbitrary commands.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1190` Exploit Public-Facing Application
Execution	`T1059` Command and Scripting Interpreter

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: CVE-2023-22518 Exploitation Attempt - Suspicious Confluence Child Process (Windows)
id: 1ddaa9a4-eb0b-4398-a9fe-7b018f9e23db
related:
    - id: f8987c03-4290-4c96-870f-55e75ee377f4
      type: similar
status: test
description: |
    Detects exploitation attempt of CVE-2023-22518 (Confluence Data Center / Confluence Server), where an attacker can exploit vulnerable endpoints to e.g. create admin accounts and execute arbitrary commands.
references:
    - https://confluence.atlassian.com/security/cve-2023-22518-improper-authorization-vulnerability-in-confluence-data-center-and-server-1311473907.html
    - https://www.huntress.com/blog/confluence-to-cerber-exploitation-of-cve-2023-22518-for-ransomware-deployment
    - https://github.com/ForceFledgling/CVE-2023-22518
author: Andreas Braathen (mnemonic.io)
date: 2023-11-14
tags:
    - attack.execution
    - attack.t1059
    - attack.initial-access
    - attack.t1190
    - cve.2023-22518
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith:
            - '\tomcat8.exe'
            - '\tomcat9.exe'
            - '\tomcat10.exe'
        ParentCommandLine|contains: 'confluence'
    selection_child:
        # Note: Only children associated with known campaigns
        - Image|endswith:
              - '\cmd.exe'
              - '\powershell.exe'
        - OriginalFileName:
              - 'Cmd.Exe'
              - 'PowerShell.EXE'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_parent`

selection_parent:
    ParentImage|endswith:
        - '\tomcat8.exe'
        - '\tomcat9.exe'
        - '\tomcat10.exe'
    ParentCommandLine|contains: 'confluence'

Stage 2: `selection_child`

selection_child:
    - Image|endswith:
          - '\cmd.exe'
          - '\powershell.exe'
    - OriginalFileName:
          - 'Cmd.Exe'
          - 'PowerShell.EXE'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\cmd.exe` corpus 130 (sigma 130) `\powershell.exe` corpus 179 (sigma 178, kusto 1)	`field:"Image" kind:ends_with`
`OriginalFileName`	eq	`Cmd.Exe` corpus 81 (sigma 43, elastic 21, splunk 17) `PowerShell.EXE` corpus 138 (sigma 84, splunk 30, elastic 24)	`field:"OriginalFileName" kind:eq`
`ParentCommandLine`	match	`confluence` corpus 2 (sigma 2)	`field:"ParentCommandLine" kind:match value:"confluence"`
`ParentImage`	ends_with	`\tomcat10.exe` `\tomcat8.exe` `\tomcat9.exe`	`field:"ParentImage" kind:ends_with`