Vulnerability Intelligence Report
Microsoft Exchange Server Security Feature Bypass Vulnerability
CVE-2021-31207
Microsoft Exchange Server Security Feature Bypass Vulnerability
CISA KEV
SSVC: Active Exploitation
CVSS Base Score
6.6
MEDIUM
Exploitability:0.8
Impact Score:5.9
EPSS Probability:99.78%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-434 ↗CWE-434 Unrestricted Upload of File with Dangerous Type
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 23 | 15.00.0 < 15.00.1497.018 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 9 | 15.02.0 < 15.02.0858.012 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 20 | 15.01.0 < 15.01.2242.010 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 19 | 15.01.0 < 15.01.2176.014 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 8 | 15.02.0 < 15.02.0792.015 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Microsoft Corporation · Vendor · USA |
| Reserved | 2021-04-14T00:00:00 |
| Published | 2021-05-11T19:11:41 |
| Patch Date | 2021-05-11 |
| Last Updated | 2025-10-21T23:25:45 |
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