What is CVE-2020-10143?

CVE-2020-10143 is a high-severity vulnerability in Macrium Reflect, classified under Improper Access Control. CVSS score: 7.8/10. Published 2020-12-09.

How severe is CVE-2020-10143?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2020-10143 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Macrium Reflect

CVE-2020-10143

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.

Published 2020-12-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (48.9th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000

Affected products

Macrium Reflect — versions 7.2, 7.3

Weakness classification (CWE)

Public proof-of-concept exploits

References

www.kb.cert.org/vuls/id/760767 (US Government Resource, Third Party Advisory)

Frequently asked questions

What is CVE-2020-10143?: CVE-2020-10143 is a high-severity vulnerability in Macrium Reflect, classified under Improper Access Control. CVSS score: 7.8/10. Published 2020-12-09.
How severe is CVE-2020-10143?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2020-10143 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.