Advisory Details

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Advantech WebAccess/HMI Designer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the parsing of PM3 files. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process.

This vulnerability is being disclosed publicly without a patch in accordance with the ZDI 120 day deadline.

11/24/20 - ZDI reported the vulnerabilities to ICS-CERT
03/31/21 - ZDI requested an update
04/02/20 - ICS-CERT confirmed receipt of the reports
04/06/21 - ZDI requested an update
04/13/21 - ICS-CERT communicated that the cases had been fixed
04/08/21 - ZDI requested an advisory
04/08/21 - ICS-CERT confirmed that an advisory draft would be provided by the following week
04/14/21 - ICS-CERT requested technical clarification
04/15/21 - ZDI provided additional evidence
04/20/21 - ZDI notified ICS-CERT of the intention to publish this report as a 0-day advisories on 04/28/21

-- Mitigation:
Given the nature of the vulnerability the only salient mitigation strategy is to restrict interaction with the application.

• 2020-11-24 - Vulnerability reported to vendor
• 2021-06-24 - Coordinated public release of advisory