Macrium Reflect includes an OpenSSL component that specifies an OPENSSLDIR variable as C:\openssl. Macrium Reflect contains a privileged service that uses this OpenSSL component. Because unprivileged Windows users can create subdirectories off of the system root, a user can create the appropriate path to a specially-crafted openssl.cnf file to achieve arbitrary code execution with SYSTEM privileges.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-10143
• https://www.kb.cert.org/vuls/id/760767