CVE-2021-31209
Microsoft Exchange Server Spoofing Vulnerability
MEDIUM
6.5
CVSS Score
Published: May 11, 2021 at 07:11 PM UTC
Updated: June 17, 2026 at 03:51 AM UTC
1 product affected across 1 vendorExchange Server
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Severity
MEDIUM6.5
Exploit prediction
EPSS 3%
SSVC
No known exploit
Description
Microsoft Exchange Server Spoofing Vulnerability
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
15.00.0 ≤ v < 15.00.1497.01815.01.0 ≤ v < 15.01.2176.01415.01.0 ≤ v < 15.01.2242.01015.02.0 ≤ v < 15.02.0792.01515.02.0 ≤ v < 15.02.0858.01215.00.015.01.015.02.020132013 cumulative_update_2320162016 cumulative_update_192016 cumulative_update_2020192019 cumulative_update_82019 cumulative_update_9
Affected range stops below 15.00.1497.018, so it looks safe — our inference, not a vendor statement
Affected range stops below 15.01.2176.014, so it looks safe — our inference, not a vendor statement
Affected range stops below 15.01.2242.010, so it looks safe — our inference, not a vendor statement
Affected range stops below 15.02.0792.015, so it looks safe — our inference, not a vendor statement
Affected range stops below 15.02.0858.012, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
References (2)
x_refsource_MISCPatchVendor Advisory
Source: [email protected]
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31209x_refsource_MISCThird Party AdvisoryVDB Entry
Source: [email protected]
https://www.zerodayinitiative.com/advisories/ZDI-21-615/SSVC — Action Prioritization
SSVCNo known exploitNot automatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
6.5MEDIUMmicrosoft
Vector?
Quick Info
StatusMODIFIED
CWE
NVD-CWE-noinfoCWE-290
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