Moxa OnCell G3100-HSPA Series

CVSS v3 9.8

**ATTENTION:**Remotely exploitable/low skill level to exploit.

Vendor: Moxa

Equipment: OnCell G3100-HSPA Series

Vulnerabilities: Reliance on Cookies without Validation and Integrity Checking, Improper Handling of Length Parameter Inconsistency, NULL Pointer Dereference

AFFECTED PRODUCTS

The following versions of OnCell, a high-speed industrial-grade IP gateway, are affected:

• OnCell G3100-HSPA Series version 1.4 Build 16062919 and prior.

IMPACT

Successful exploitation of these vulnerabilities may allow an attacker to remotely execute code on the device.

MITIGATION

Moxa has released new firmware for OnCell G3100-HSPA that is available via the following link:

https://www.moxa.com/support/download.aspx?type=support&id=13668

NCCIC recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

NCCIC also provides a section for control systems security recommended practices on the ICS-CERT web page. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available in the NCCIC Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to NCCIC for tracking and correlation against other incidents.

No known public exploits specifically target these vulnerabilities.

VULNERABILITY OVERVIEW

RELIANCE ON COOKIES WITHOUT VALIDATION AND INTEGRITY CHECKING CWE-565

The application allows a cookie parameter to consist of only digits, allowing an attacker to perform a brute force attack bypassing authentication and gaining access to device functions.

CVE-2018-5455 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

IMPROPER HANDLING OF LENGTH PARAMETER INCONSISTENCY CWE-130

An attacker may be able to edit the element of an HTTP request, causing the device to become unavailable.

CVE-2018-5453 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

NULL POINTER DEREFERENCE CWE-476

The application does not check for a NULL value, allowing for an attacker to perform a denial of service attack.

CVE-2018-5449 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been assigned; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

RESEARCHER

Kirill Nesterov, Eugenie Potseluevskaya, and Radu Motspan of Kaspersky Labs reported the vulnerabilities to NCCIC.

BACKGROUND

Critical Infrastructure Sectors: Commercial Facilities, Critical Manufacturing, Transportation Systems

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Taiwan