NXP Semiconductors MQX RTOS

CVSS v3 8.1

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

Vendor: NXP Semiconductors

Equipment: MQX RTOS

**Vulnerabilities:**Classic Buffer Overflow, Out-of-Bounds Read

AFFECTED PRODUCTS

The following versions of MQX Real-Time Operating System (RTOS) are used in NXP’s ColdFire microcontrollers, Kinetis microcontrollers, i.MX processors, and Vybrid processors, which are affected by the vulnerabilities listed below.

Versions susceptible to Classic Buffer Overflow Vulnerability:

• MQX RTOS, Version 5.0 and prior versions, and

Versions susceptible to Out-of-Bounds Read Vulnerability:

• MQX RTOS, Version 4.1 and prior versions.

IMPACT

Successful exploitation of these vulnerabilities may allow a remote attacker to cause a buffer overflow condition that may, in turn, cause remote code execution or out-of-bounds read conditions, resulting in a denial of service.

MITIGATION

NXP is planning to release a product fix for MQX, Version 5.1, by January 2018, which will address both vulnerabilities. Until the product fix can be applied, NXP recommends that users consider implementing the following interim mitigations to limit the risk of exploitation of the identified vulnerabilities:

• For MQX users running Version 5.0, NXP has produced a code modification that can be applied prior to the release of Version 5.1. Users can contact NXP directly via email at [email protected] to get additional information.
• For MQX users running Version 4.1 and prior versions, NXP recommends that users update to Version 4.2 or Version 5.0, which do not contain the out-of-bounds read vulnerability.

NCCIC/ICS-CERT recommends that 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.

ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

ICS-CERT 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 ICS‑CERT 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 ICS-CERT for tracking and correlation against other incidents.

No known public exploits specifically target these vulnerabilities.

VULNERABILITY OVERVIEW

BUFFER COPY WITHOUT CHECKING SIZE OF INPUT (‘CLASSIC BUFFER OVERFLOW’) CWE-120

The Real-Time TCP/IP Communications Suite (RTCS) in MQX’s DHCP client fails to sanitize all inputs, which may allow maliciously crafted DHCP packets to cause memory to be overwritten, allowing remote code execution.

CVE-2017-12718 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been assigned; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).

OUT-OF-BOUNDS READ CWE-125

The DNS client for MQX fails to bounds check DNS response parameters, which may allow maliciously crafted DNS packets to cause memory to be read out-of-bounds, resulting in a denial of service.

CVE-2017-12722 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

RESEARCHER

Scott Gayou identified and coordinated these vulnerabilities with NXP, CERT/CC, and ICS-CERT.

BACKGROUND

Critical Infrastructure Sectors: Communications, Critical Manufacturing, Healthcare and Public Health, and Transportation

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Eindhoven, Netherlands