1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low skill level to exploit
- Vendor: Advantech
- Equipment: DiagAnywhere Server
- Vulnerability: Stack-based Buffer Overflow
2. RISK EVALUATION
Successful exploitation of this vulnerability may allow remote code execution.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of DiagAnywhere Server, used for remotely monitoring and controlling other Windows based devices, are affected:
- DiagAnywhere Server Versions 3.07.11 and prior
3.2 VULNERABILITY OVERVIEW
3.2.1 STACK-BASED BUFFER OVERFLOW CWE-121
Multiple stack-based buffer overflow vulnerabilities exist in the file transfer service listening on the TCP port. Successful exploitation could allow an unauthenticated attacker to execute arbitrary code with the privileges of the user running DiagAnywhere Server.
CVE-2019-18257 has been assigned to these vulnerabilities. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/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, United States, and Europe
- COMPANY HEADQUARTERS LOCATION: Taiwan
3.4 RESEARCHER
Z0mb1E working with Trend Micro’s Zero Day Initiative, reported this vulnerability to CISA.
4. MITIGATIONS
Advantech has phased out DiagAnywhere Server Version 3.07.11 and removed it from its website.
Advantech has released Version 3.07.14 of DiagAnywhere Server to address the reported vulnerability. Users can download the latest version of DiagAnywhere Server by accessing the Advantech Support Portal at DiagAnywhere Server update.
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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.
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 on us-cert.gov. 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 on the ICS webpage on us-cert.gov in the Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability.
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