CVE-2022-26022

Executive Summary

CVE-2022-26022 is an out-of-bounds write vulnerability in Omron CX-Position, a configuration and programming tool for Omron position control units. An attacker who can trick a user into opening a specially crafted project file can achieve arbitrary code execution on the victim's engineering workstation. The vulnerability carries a CVSS v3 score of 7.8 (High) due to the potential for full system compromise, but requires local user interaction, which limits the attack surface to phishing or supply-chain scenarios. A patch (version 2.5.4) exists but is only available to paying customers via Omron's Auto Update function, and its authenticity has not been independently confirmed.

As a component of the broader industrial control system (ICS) engineering ecosystem, successful exploitation could provide lateral movement opportunities into production environments or allow an attacker to modify PLC logic and parameters.

Technical Analysis

Vulnerability Class: CWE-787 (Out-of-Bounds Write)

CX-Position is a desktop application used to configure Omron CJ-series and CS-series position control units. The vulnerability stems from insufficient memory boundary validation while parsing a specific project file format. The affected software reads serialized data from the file into stack or heap buffer without proper size checking, potentially allowing a write operation to extend beyond the intended buffer boundary.

The out-of-bounds write allows an attacker to corrupt adjacent memory regions. Under typical exploitation, this can be directly leveraged for arbitrary code execution in the context of the logged-in user. The vulnerability requires that user open a malformed file, meaning the threat actor needs to deliver this file via email, a compromised website, or shared network storage.

The project file format is not publicly documented, complicating analysis and generic YARA rule creation. However, the nature of the flaw means that the malicious content must use specific magic bytes or a sequence, either in the header, chunk declarations, or data section, that triggers the write overflow. The result is that any data read from the file and subsequently written into memory without bounds checking will result in the overflow.

Attack Surface:

• Local Attack Vector: The attacker must convince a user to open the malicious project file.
• Engineering Workstations: The biggest risk is to critical infrastructure environments, especially those using Omron position control units for automation.
• Supply Chain Risk: A malicious actor could tamper with project files shared within a production team, or via an OEM/vendor partnership, to compromise downstream users.

Exploitation Scenarios

Note: No public PoC or exploit code is available for CVE-2022-26022. The attack chain below is inferred from the vulnerability class and the software's usage context, not from verified public details.

Attack Chain Steps

1. Reconnaissance / Target Identification

• The attacker identifies a target business or enterprise that uses Omron CX-Position software. May be discovered through job postings (tools mentioned), Shodan for exposed ICS management interfaces, or by targeting organizations in manufacturing, packaging, and utilities with PLC-based automation.
• Possible Shodan queries: country:US "CX-Position", http.title:"OMRON", port:22,3389 "OMRON".

2. Triggering the Flaw Class

• The attacker crafts a malicious .px2 (or other CX-Position project file extension) with a specific structure that produces a write operation beyond the intended buffer. While the technical details of the exact overflow remain undisclosed, the file is crafted so that upon load, the software writes a greater length of data into a fixed-size buffer than the buffer can hold.
• Attack is delivered via a phishing email with a PDF or ZIP attachment, or a luring website offering a "configuration file" or "firmware update."

3. Payload / Execution Method (Vulnerability-Class Level)

• The overflow overwrites adjacent memory (e.g., return address or function pointer) enabling the attacker to redirect execution to shellcode injected into the same file. Typically, shellcode executes a "calc.exe" or more complex command to download a second-stage payload.
• In absence of a proper exploit mitigation (like ASLR/DEP bypass), shellcode may call Windows API functions to spawn a reverse shell or create a new local admin account since the process runs in the user space.

4. Post-Exploitation Impact

• With code execution, the attacker gains remote access to the engineering workstation.
• Lateral movement - Credentials may be logged for engineering protocols (e.g., EtherNet/IP, Modbus TCP) or stored in the project files.
• PLC Program Modification - If on the same network, the attacker can upload new logic to the position control unit, altering machine behavior (sabotage) or bringing processes to a halt.
• Ransomware / IP Theft - Ability to exfiltrate proprietary PLC programs and engineering documentation.

Impact Assessment

Affected Systems:

• Omron CX-Position versions 2.5.3 and prior running on Windows (32-bit/64-bit workstations).

Business Impact Examples:

1. Production Downtime: An attacker alters the position control unit parameters, causing an assembly line to malfunction.
2. Safety Impact: In automated machinery, changing movement boundaries can cause physical damage or injury.
3. Ransomware Entry Point: Engineering workstations often have network access to critical ICS systems; ransomware deployed here can propagate.

Detection Guidance

No public signatures exist for this CVE, so the following detections are based on anomaly-based logic and generic exploit detection concepts.

Sigma Rule

title: Suspicious CX-Position Project File Access
id: 8a9b2b3e-9d04-4c3c-9c52-6b422993c3e0
status: experimental
description: Detects attempts to open a CX-Position project file from unusual locations or with unusual file characteristics.
author: Valtersit Threat Intel
date: 2025/03/20
logsource:
  category: file_event
  product: windows
detection:
  selection:
    TargetFilename|endswith:
      - '.px2'
      - '.pxp'
  filter_suspicious_paths:
    TargetFilename|contains:
      - '\AppData\'
      - '\Temp\'
      - '\Downloads\'
  condition: selection and filter_suspicious_paths
level: high

YARA Rule

rule CVE_2022_26022_CXPosition_Suspicious
{
    meta:
        author = "Valtersit Threat Intel"
        description = "Detects potentially malformed CX-Position project files. Based on likely header bytes and overly long field lengths."
        cve = "CVE-2022-26022"
        date = "2025-03-20"
    strings:
        $header = { 4F 4D 52 4F 4E 43 58 }  // "OMRONCX" - typical header
        $magic = { 50 58 32 }  // "PX2" file magic
        $long_field = { 00 00 01 00 }  // Possibly a length field (nonspecific)
    condition:
        ($magic at 0 or $header at 0) and #long_field > 10
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2022-26022 - Suspicious CX-Position Project File Download"; flow:established,to_client; content:"Content-Type|3a| application/octet-stream"; content:".px2"; http.uri; xbits:set,omron.download,ttl 300; sid:1004822; rev:1;)

Elastic Detection

sequence by process.executable with maxspan=15s
  [process where event.action == "exec" and process.name == "cx-position.exe"]
  [file where event.action in ("open", "read") and file.extension in ("px2", "pxp") and
   file.path == "*Downloads*" and file.size > 500000]

Splunk SPL Query

(index=windows OR index=endpoint) source="WinEventLog:Microsoft-Windows-Sysmon/Operational"
| search EventCode=11 (TargetFilename="*.px2" OR TargetFilename="*.pxp")
| eval dest_host=mvsysinfo
| table _time, dest_host, User, TargetFilename, Image
| where TargetFilename LIKE "%Downloads%" OR TargetFilename LIKE "%Temp%"

Wazuh OSSEC Rule

<group name="CVE-2022-26022,">
  <rule id="453648" level="12">
    <decoded_as>sysmon</decoded_as>
    <field name="win.system.EventID">11</field>
    <description>CVE-2022-26022 - Potential CX-Position malicious project file opened</description>
    <match>\.px2|\.pxp</match>
    <field name="win.eventdata.targetFilename">\.(px2|pxp)$</field>
    <group>ics,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 2/4 (CLAIMED — single source claims patch, not independently confirmed)

1. Immediate Mitigations

• Restrict user permissions to only those needed; enforce least privilege on engineering workstations.
• Block file extensions .px2 and .pxp in corporate email gateway and Microsoft 365/Exchange transport rules.
• Deploy application whitelisting (e.g., AppLocker) to prevent execution of unknown binaries from temp directories.
• Isolate engineering workstations on a separate VLAN from the broader corporate network and enforce Firewall rules to limit egress.
• Ensure Windows Defender Exploit Guard (or equivalent) is enabled with ASLR and DEP.

2. Patch / Upgrade Steps

• Contact Omron Technical Support or an authorized Omron representative to obtain version 2.5.4.
• If you are a paying customer, use the built-in "Auto Update" function in CX-Position to download the fix.
• Validate hash of the update file against Omron’s provided checksums before installation.
• After installation, verify version via Help → About.

3. Long-Term Hardening

• Implement email security controls that sandbox attachments before delivery.
• Train engineering staff to recognize phishing and social engineering attempts targeting ICS tooling.
• Establish a vendor-managed update process for all ICS engineering tools.
• Monitor vendor security advisories (Omron, JPCERT/CC, CISA) for new versions or workarounds.

References

1. NVD Entry: CVE-2022-26022 - NVD
2. CNA Record: Rockwell Automation Studio 5000 Logix Designer Out-of-Bounds Write (via CNA, likely cross-referenced with Omron)
3. Omron Security Advisories: Omron Security (check for CX-Position-specific note)
4. CISA ICS-CERT Advisories: ICS-CERT Advisories — search for CVE-2022-26022
5. EPSS Data: FIRST EPSS — CVE-2022-26022

No known threat actor campaigns or exploitation in the wild have been reported for this CVE at the time of writing. The lack of public PoC and the niche nature of the tool reduce the likelihood of mass exploitation.