CVE-2021-31207

Microsoft Exchange Server — Microsoft Exchange Server Security Feature Bypass Vulnerability
⚠️ CVSS 3.1  6.6 / 10 — MEDIUM 🔴 CISA Known Exploited Vulnerability

Overview

Microsoft Exchange Server contains an unspecified vulnerability that allows for security feature bypass.

https://nvd.nist.gov/vuln/detail/CVE-2021-31207

Key Details

PropertyValue
CVE ID CVE-2021-31207
Vendor / Product Microsoft — Exchange Server
NVD Published2021-05-11
NVD Last Modified2025-10-30
CVSS 3.1 Score6.6
CVSS 3.1 VectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
SeverityMEDIUM
CWE CWE-434
CISA KEV Added2021-11-03
CISA KEV Deadline2021-11-17
Known Ransomware Use ⚠️ Yes

CVSS 3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Required Action

CISA BOD 22-01 Deadline: 2021-11-17. Apply updates per vendor instructions.

Timeline

DateEvent
2021-11-03Added to CISA Known Exploited Vulnerabilities catalog
2021-11-17CISA BOD 22-01 remediation deadline

References

ResourceType
NVD — CVE-2021-31207 Vulnerability Database
CISA KEV Catalog Entry US Government