Successful exploitation of these vulnerabilities could allow an attacker to gain remote code execution.
The following versions of WebAccess, an HMI platform, are affected:
The affected product is vulnerable to a heap-based buffer overflow, which may allow an attacker to remotely execute code.
CVE-2021-33023 has been assigned to this vulnerability. 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).
The affected product is vulnerable to a stack-based buffer overflow, which may allow an attacker to remotely execute code.
CVE-2021-38389 has been assigned to this vulnerability. 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).
Natnael Samson, @NattiSamson, working with Trend Microβs Zero Day Initiative, reported these vulnerabilities to CISA.
Advantech has released Version 9.1.1 to address the stack-based buffer overflow vulnerability.
In order to address the heap-based buffer overflow vulnerability, Advantech recommends users directly add the remote access code to avoid being attacked by unknown requests. This is the remote access code established during installation of the Advantech WebAccess SCADA software (SCADA node, project node, or OPC Service) on the OPC Server computer. The access code you enter here must match the remote access code established during installation on the OPC Server. This prevents unauthorized users from accessing the OPC Server data using the Advantech WebAccess SCADA OPC Service.
If you have forgotten the remote access code using during software installation on the OPC Server node, you have two options:
CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:
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-12-146-01BβTargeted 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 these vulnerabilities.
220.130.135.6/broadWeb/engman/20.5_UPDATE.htm
220.130.135.6/broadWeb/engman/25.5_BWSERVER.INI.htm
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