1. EXECUTIVE SUMMARY
- CVSS v3 5.4
- ATTENTION: Exploitable remotely/low skill level to exploit
- Vendor: Advantech
- Equipment: WebAccess/SCADA
- Vulnerability: Cross-site Scripting
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow an unauthorized user to steal a user’s cookie/session token or redirect an authorized user to a malicious webpage.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of WebAccess/SCADA, a browser-based SCADA software package, are affected:
- WebAccess/SCADA Versions 9.0 and prior
3.2 VULNERABILITY OVERVIEW
3.2.1 IMPROPER NEUTRALIZATION OF INPUT DURING WEB PAGE GENERATION (‘CROSS-SITE SCRIPTING’) CWE-79
CVE-2021-27436 has been assigned to this vulnerability. A CVSS v3 base score of 5.4 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N).
- CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing, Energy, Water and Wastewater Systems
- COUNTRIES/AREAS DEPLOYED: East Asia, Europe, United States
- COMPANY HEADQUARTERS LOCATION: Taiwan
Chizuru Toyama of TXOne IoT/ICS Security Research Labs of Trend Micro, working with Trend Micro’s Zero Day Initiative, reported this vulnerability to CISA.
Advantech recommends users update to Version 9.0.1 or later.
CISA recommends users take the following measures to protect themselves from social engineering attacks:
- Do not click web links or open unsolicited attachments in email messages.
- Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
- Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.
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.cisa.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.cisa.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.