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 the length of user-supplied data prior to copying it to a fixed-length heap-based 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.

• 2020-12-02 - Vulnerability reported to vendor
• 2021-04-28 - Coordinated public release of advisory