CVE-2021-34473
critical
Microsoft
⚠️ CISA KEV — Exploited in the Wild
CVSS v3 Base Score
9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score
100.0%
Exploitation probability in 30 days
Top 0% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
None
Published: July 14, 2021 (1879 days ago)
Last Modified: August 10, 2026
Vendor: Microsoft
Source: NVD
⚠️ CISA Known Exploited Vulnerability
Added to KEV: 2021-11-03
Remediation Due: 2021-11-17 (⚠ 1754d overdue)
Ransomware Campaign: Known
Vulnerability Report
Generated by CyberWatcher
Description
Microsoft Exchange Server Remote Code Execution Vulnerability
CWE
CWE-918Affected Products
microsoft exchange server