Contec Health CMS8000

1. EXECUTIVE SUMMARY

• CVSS v3 7.5
• ATTENTION: Low attack complexity
• Vendor: Contec Health
• Equipment: CMS8000 CONTEC ICU CCU Vital Signs Patient Monitor
• Vulnerabilities: Improper Access Control, Uncontrolled Resource Consumption, Use of Hard-Coded Credentials, Active Debug Code

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow a threat actor to cause a denial-of-service condition, modify firmware with physical access to the device, access a root shell, or employ hard-coded credentials to make configuration changes.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following Contec Health products are affected:

• Contec Health CMS8000 CONTEC ICU CCU Vital Signs Patient Monitor

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER ACCESS CONTROLS CWE-284

A threat actor with momentary access to the device can plug in a USB drive and perform a malicious firmware update, resulting in permanent changes to device functionality. No authentication or controls are in place to prevent a threat actor from maliciously modifying firmware and performing a drive-by attack to load the firmware on any CMS8000 device.

CVE-2022-36385 has been assigned to this vulnerability. A CVSS v3 base score of 6.8 has been calculated; the CVSS vector string is (AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.2    UNCONTROLLED RESOURCE CONSUMPTION CWE-400

The CMS800 device fails while attempting to parse malformed network data sent by a threat actor. A threat actor with network access can remotely issue a specially formatted UDP request that will cause the entire device to crash and require a physical reboot. A UDP broadcast request could be sent that causes a mass denial-of-service attack on all CME8000 devices connected to the same network.

CVE-2022-38100 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

3.2.3    USE OF HARD-CODED CREDENTIALS CWE-798

Multiple globally default credentials exist across all CMS8000 devices, that once exposed, allow a threat actor with momentary physical access to gain privileged access to any device. Privileged credential access enables the extraction of sensitive patient information or modification of device parameters.

CVE-2022-38069 has been assigned to this vulnerability. A CVSS v3 base score of 4.3 has been calculated; the CVSS vector string is (AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

3.2.4    ACTIVE DEBUG CODE CWE-489

Multiple binary application files on the CMS8000 device are compiled with 'not stripped' and 'debug_info' compilation settings. These compiler settings greatly decrease the level of effort for a threat actor to reverse engineer sensitive code and identify additional vulnerabilities.

CVE-2022-38453 has been assigned to this vulnerability. A CVSS v3 base score of 3.0 has been calculated; the CVSS vector string is (AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N).

3.2.5    IMPROPER ACCESS CONTROL CWE-284

The CMS8000 device does not properly control or sanitize the SSID name of a new Wi-Fi access point. A threat actor could create an SSID with a malicious name, including non-standard characters that, when the device attempts connecting to the malicious SSID, the device can be exploited to write arbitrary files or display incorrect information.

CVE-2022-3027 has been assigned to this vulnerability. A CVSS v3 base score of 5.7 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Healthcare and Public Health
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: China

3.4 RESEARCHER

Level Nine reported these vulnerabilities to CISA.

4. MITIGATIONS

Contec Health has not responded to requests to work with CISA to mitigate these vulnerabilities. Users of these affected products are invited to contact Contec Health for additional information.

The following mitigations could assist in reducing the risk for exploitation of vulnerabilities:

• Disabling UART functionality at the CPU level
• Enforcing unique device authentication before granting access to the terminal / bootloader
• Where possible, enforcing secure boot. 
• Tamper stickers on the device casing to indicate when a device has been opened

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

• Secure physical access.
• Minimize network exposure for all control system devices and/or systems, and ensure 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 VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

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

CISA also provides a section for control systems security recommended practices on the ICS webpage at cisa.gov/ics. Several CISA products detailing cyber defense best 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 on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

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

No known public exploits specifically target these vulnerabilities. These vulnerabilities are not exploitable remotely.

• Contec Health