CVE-2026-89208: Siemens Capital Embedded AR Classic Out-of-Bounds Read — Detection and Remediation Guide

---
title: Siemens Capital Embedded AR Classic Process Crash
description: Detects unexpected crashes or abnormal termination of Siemens Capital Embedded AR Classic processes, potentially indicating exploitation of CVE-2026-89208.
status: experimental
references:
  - https://www.cisa.gov/news-events/ics-advisories/icsa-26-295-04
author: Security Arsenal
date: 2026/10/22
tags:
  - attack.impact
  - attack.t1499
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    EventID: 4688
    NewProcessName|endswith:
      - 'capital.exe'
      - 'capital_embedded.exe'
      - 'arclassic.exe'
    CommandLine|contains:
      - 'Capital Embedded AR Classic'
  condition: selection
falsepositives:
  - Legitimate application restarts during updates or maintenance
level: medium
---
title: Abnormal Memory Access by Capital Embedded AR Classic
description: Detects potential out-of-bounds read attempts or abnormal memory access patterns by Siemens Capital Embedded AR Classic processes.
status: experimental
references:
  - https://www.cisa.gov/news-events/ics-advisories/icsa-26-295-04
author: Security Arsenal
date: 2026/10/22
tags:
  - attack.impact
  - attack.t1499
logsource:
  category: process_access
  product: windows
detection:
  selection:
    TargetImage|endswith:
      - 'capital.exe'
      - 'capital_embedded.exe'
      - 'arclassic.exe'
    GrantedAccess:
      - '0x1FFFFF'
      - '0x1F3FFF'
  condition: selection
falsepositives:
  - Debugging or profiling tools used by engineering teams
level: low
---
title: Network Connection by Siemens Capital Embedded AR Classic
description: Detects outbound network connections from Capital Embedded AR Classic processes, which may indicate exploitation attempts or data exfiltration.
status: experimental
references:
  - https://www.cisa.gov/news-events/ics-advisories/icsa-26-295-04
author: Security Arsenal
date: 2026/10/22
tags:
  - attack.exfiltration
  - attack.t1041
logsource:
  category: network_connection
  product: windows
detection:
  selection:
    Image|endswith:
      - 'capital.exe'
      - 'capital_embedded.exe'
      - 'arclassic.exe'
    Initiated: 'true'
  condition: selection
falsepositives:
  - Legitimate license server communication or cloud synchronization
level: informational

// Hunt for crashes or abnormal terminations of Capital Embedded AR Classic processes
DeviceProcessEvents
| where FileName in~ ("capital.exe", "capital_embedded.exe", "arclassic.exe")
| where ProcessCommandLine contains "Capital Embedded AR Classic"
| project Timestamp, DeviceName, FileName, ProcessCommandLine, InitiatingProcessFileName, InitiatingProcessCommandLine
| order by Timestamp desc

// Hunt for abnormal memory access patterns by Capital Embedded AR Classic
DeviceEvents
| where ActionType == "ProcessMemoryAccess"
| where InitiatingProcessFileName in~ ("capital.exe", "capital_embedded.exe", "arclassic.exe")
| project Timestamp, DeviceName, InitiatingProcessFileName, InitiatingProcessCommandLine, FileName, FolderPath
| order by Timestamp desc

// Hunt for network connections from Capital Embedded AR Classic processes
DeviceNetworkEvents
| where InitiatingProcessFileName in~ ("capital.exe", "capital_embedded.exe", "arclassic.exe")
| where ActionType == "ConnectionSuccess"
| project Timestamp, DeviceName, InitiatingProcessFileName, RemoteIP, RemotePort, RemoteUrl
| order by Timestamp desc

-- Hunt for Capital Embedded AR Classic processes and their network connections
SELECT Pid, Name, CommandLine, Exe, Username, CreateTime
FROM pslist()
WHERE Name =~ '(capital|arclassic)' OR CommandLine =~ 'Capital Embedded AR Classic'

-- Hunt for network connections from Capital Embedded AR Classic
SELECT Pid, Name, CommandLine, LocalAddress, LocalPort, RemoteAddress, RemotePort, State
FROM netstat()
WHERE Name =~ '(capital|arclassic)' OR CommandLine =~ 'Capital Embedded AR Classic'

-- Hunt for file artifacts related to Capital Embedded AR Classic
SELECT FullPath, Size, Mtime, Atime, Ctime
FROM glob(globs='C:/Program Files*/Siemens/Capital Embedded AR Classic/**/*')
WHERE Mtime > ago(30d)

# Siemens Capital Embedded AR Classic Version Verification and Patch Check
# Run as Administrator

Write-Host "=== Siemens Capital Embedded AR Classic Version Check ===" -ForegroundColor Cyan

# Check for installed versions
$installed = Get-WmiObject -Class Win32_Product | Where-Object { $_.Name -like "*Capital Embedded AR Classic*" }

if ($installed) {
    $installed | ForEach-Object {
        Write-Host "Product: $($_.Name)" -ForegroundColor Green
        Write-Host "Version: $($_.Version)" -ForegroundColor Yellow
        
        # Check if version is vulnerable
        if ($_.Version -match "^431-422") {
            Write-Host "[VULNERABLE] This version is affected by CVE-2026-89208. No patch available yet. Apply countermeasures." -ForegroundColor Red
        } elseif ($_.Version -match "^R20-11" -and $_.Version -lt "2303") {
            Write-Host "[VULNERABLE] This version is affected by CVE-2026-89208. Update to version 2303 or later." -ForegroundColor Red
        } else {
            Write-Host "[OK] This version appears to be patched or not affected." -ForegroundColor Green
        }
    }
} else {
    Write-Host "Siemens Capital Embedded AR Classic not found on this system." -ForegroundColor Yellow
}

# Check for running processes
Write-Host "`n=== Running Processes ===" -ForegroundColor Cyan
$processes = Get-Process | Where-Object { $_.ProcessName -match "capital|arclassic" }
if ($processes) {
    $processes | Select-Object ProcessName, Id, Path | Format-Table -AutoSize
} else {
    Write-Host "No Capital Embedded AR Classic processes currently running." -ForegroundColor Green
}

# Check for network listeners
Write-Host "`n=== Network Listeners ===" -ForegroundColor Cyan
$listeners = Get-NetTCPConnection | Where-Object { $_.OwningProcess -in ($processes.Id) -and $_.State -eq "Listen" }
if ($listeners) {
    $listeners | Select-Object LocalAddress, LocalPort, OwningProcess | Format-Table -AutoSize
    Write-Host "[WARNING] Capital Embedded AR Classic is listening on network ports. Ensure network segmentation is in place." -ForegroundColor Yellow
} else {
    Write-Host "No network listeners detected for Capital Embedded AR Classic." -ForegroundColor Green
}

Write-Host "`n=== Recommendations ===" -ForegroundColor Cyan
Write-Host "1. Update Capital Embedded AR Classic R20-11 to version 2303 or later." -ForegroundColor White
Write-Host "2. For Capital Embedded AR Classic 431-422, apply Siemens-recommended countermeasures until a patch is available." -ForegroundColor White
Write-Host "3. Restrict network access to Capital Embedded AR Classic instances using firewall rules." -ForegroundColor White
Write-Host "4. Monitor for abnormal process behavior or crashes using the detection rules in this advisory." -ForegroundColor White