1. EXECUTIVE SUMMARY

CVSS v3 7.2 
ATTENTION: Exploitable remotely/low attack complexity
Vendor: Advantech
Equipment: WebAccess Node
Vulnerabilities: Improper Control of Generation of Code (‘Code Injection’), Unrestricted Upload of File with Dangerous Type

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an attacker to arbitrarily overwrite files resulting in remote code execution.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following Advantech products are affected:

WebAccess/SCADA versions 9.1.3 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1 IMPROPER CONTROL OF GENERATION OF CODE (‘CODE INJECTION’) CWE-94

In Advantech WebAccss/SCADA v9.1.3 and prior, there is an arbitrary file overwrite vulnerability, which could allow an attacker to overwrite any file in the operating system (including system files), inject code into an XLS file, and modify the file extension, which could lead to arbitrary code execution.

CVE-2023-32540 has been assigned to this vulnerability. A CVSS v3 base score of 7.2 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).

3.2.2 UNRESTRICTED UPLOAD OF FILE WITH DANGEROUS TYPE CWE-434

In Advantech WebAccss/SCADA v9.1.3 and prior, there is an arbitrary file upload vulnerability that could allow an attacker to upload an ASP script file to a webserver when logged in as manager user, which can lead to arbitrary code execution.

CVE-2023-22450 has been assigned to this vulnerability. A CVSS v3 base score of 7.2 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).

3.2.3 UNRESTRICTED UPLOAD OF FILE WITH DANGEROUS TYPE CWE-434

In Advantech WebAccss/SCADA v9.1.3 and prior, there is an arbitrary file upload vulnerability that could allow an attacker to modify the file extension of a certificate file to ASP when uploading it, which can lead to remote code execution.

CVE-2023-32628 has been assigned to this vulnerability. A CVSS v3 base score of 7.2 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing, Energy, Water and Wastewater Systems
COUNTRIES/AREAS DEPLOYED: East Asia, Europe, United States
COMPANY HEADQUARTERS LOCATION: Tawain

3.4 RESEARCHER

YangLiu from Elex Feigong Research Institute reported these vulnerabilities to CISA.

4. MITIGATIONS

Advantech recommends WebAccess/SCADA users upgrade to v9.1.4. 

CISA 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 they are not accessible from the Internet.
Locate control system networks and remote devices behind firewalls and isolate them from business networks.
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.