CVE-2020-0688
KEVRansomware UseMicrosoft Exchange Server Validation Key Remote Code Execution Vulnerability
Description
Microsoft Exchange Server Validation Key fails to properly create unique keys at install time, allowing for remote code execution.
A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HPublishedFeb 11, 2020
Last modifiedJun 17, 2026
Added to KEVNov 3, 2021
Remediation dueMay 3, 2022
References
- packetstormsecurity.com/files/156592/Microsoft-Exchange-2019-15.2.221.12-Remote-Code-Execution.htmlExploitThird Party Advisory
- packetstormsecurity.com/files/156620/Exchange-Control-Panel-Viewstate-Deserialization.htmlExploitThird Party Advisory
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0688PatchVendor Advisory
- zerodayinitiative.com/advisories/ZDI-20-258/Third Party AdvisoryVDB Entry
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0688US Government Resource
0 recent articles mention this CVE
94
Risk assessment · Critical
Actively exploited and used by ransomware crews. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1637 days
- Ransomware
- Used in known ransomware campaigns
- CVSS
- 8.8 HIGH
- EPSS (30-day exploit probability)
- 100.0% · top 1% of all CVEs
- Weakness
- CWE-287
- Attack vector
- Network, remotely reachable
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
- 5.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.