Full Report
[Control Systems] Moxa security advisory (AV26-393)
Analysis Summary
# Vulnerability: Moxa Secure Routers Improper Ownership Management and Length Parameter Handling
## CVE Details
- **CVE ID:** CVE-2026-3867, CVE-2026-3868
- **CVSS Score:** Not explicitly provided in the summary source (Typically High for these classes of vulnerabilities in industrial networking equipment)
- **CWE:**
- CWE-282: Improper Ownership Management
- CWE-130: Improper Handling of Length Parameter Inconsistency
## Affected Systems
- **Products:**
- TN-4900 Series
- EDR-8010 Series
- EDR-G9010 Series
- OnCell G4302-LTE4 Series
- OnCell G4308-LTE4 Series
- EDF-G1002-BP Series
- **Versions:**
- TN-4900: v3.22 and prior
- EDR-8010: v3.23 and prior
- EDR-G9010: v3.23.1 and prior
- OnCell G4302/G4308-LTE4: v3.23.0 and prior
- EDF-G1002-BP: v3.23 and prior
- **Configurations:** Systems utilizing default or insufficiently managed administrative ownership and those processing network packets/data lengths.
## Vulnerability Description
The advisory addresses two primary flaws:
1. **Improper Ownership Management (CVE-2026-3867):** This vulnerability involves the failure of the software to properly manage the "owner" of a resource. This can allow unauthorized users to gain control over critical system functions or files, potentially leading to privilege escalation.
2. **Improper Handling of Length Parameter Inconsistency (CVE-2026-3868):** This flaw occurs when the system does not properly validate or reconcile differences between different length fields in a data structure. This can lead to buffer overflows or memory corruption when the software processes malformed packets.
## Exploitation
- **Status:** Not specified as exploited in the wild (per the current advisory).
- **Complexity:** Medium (typical for memory/ownership flaws in OT hardware).
- **Attack Vector:** Network (Remote exploitation is possible if the management interface or relevant services are exposed).
## Impact
- **Confidentiality:** High (Potential for unauthorized data access).
- **Integrity:** High (Potential for unauthorized configuration changes).
- **Availability:** High (Potential for device crashes or Denial of Service (DoS)).
## Remediation
### Patches
Users are advised to upgrade to the following firmware versions (or subsequent releases):
- **TN-4900 Series:** Upgrade to v3.23 or later.
- **EDR-8010 Series:** Upgrade to v3.24 or later.
- **EDR-G9010 Series:** Upgrade to v3.23.2 or later.
- **OnCell G4302/G4308-LTE4 Series:** Upgrade to v3.23.1 or later.
- **EDF-G1002-BP Series:** Upgrade to v3.24 or later.
### Workarounds
- **Network Segmentation:** Isolate the management interfaces of Secure Routers and OnCell devices from the public internet.
- **Access Control:** Implement strict Access Control Lists (ACLs) to ensure only authorized IP addresses can access the device management ports.
- **Disable Unnecessary Services:** Turn off unused protocols or services that may be vulnerable to length parameter manipulation.
## Detection
- **Indicators of Compromise:** Monitor for unusual administrative logins, unexpected system reboots, or malformed packet alerts in system logs.
- **Detection Methods:** Utilize Industrial Intrusion Detection Systems (IIDS) to flag inconsistent packet length parameters or unauthorized ownership changes in the device configuration export.
## References
- **Vendor Advisory:** hxxps[://]www[.]moxa[.]com/en/support/product-support/security-advisory/mpsa-261521-cve-2026-3867-cve-2026-3868-improper-ownership-management-and-improper-handling-of-length-parameter-incons
- **Moxa Security Portal:** hxxps[://]www[.]moxa[.]com/en/support/product-support/security-advisory
- **Canadian Centre for Cyber Security Advisory (AV26-393):** hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/control-systems-moxa-security-advisory-av26-393