November 3, 2021 · Applied Cybernetics Group
CVE-2020-0688 — Microsoft Exchange Server
known ransomware use
Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability
- Added to KEV
2021-11-03- Federal due date
2022-05-03- Vendor
- Microsoft
- Product
- Exchange Server
- EPSS
- 100.0th percentile (score 0.944, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Known
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2020-0688
CISA short description
Microsoft Exchange Server Validation Key fails to properly create unique keys at install time, allowing for remote code execution.
Required action
Apply updates per vendor instructions.