CVE-2021-1730

Microsoft Exchange Server Spoofing Vulnerability

MEDIUM
5.4
CVSS Score
Published: February 25, 2021 at 11:01 PM UTC
Updated: June 17, 2026 at 03:32 AM UTC
1 product affected across 1 vendorExchange Server

Using Microsoft Exchange Server 2019 Cumulative Update 7 by Microsoft?

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Severity
MEDIUM5.4
Exploit prediction
EPSS 2%

Description

<p>A spoofing vulnerability exists in Microsoft Exchange Server which could result in an attack that would allow a malicious actor to impersonate the user.</p> <p>This update addresses this vulnerability.</p> <p>To prevent these types of attacks, Microsoft recommends customers to download inline images from different DNSdomains than the rest of OWA. Please see further instructions in the FAQ to put in place this mitigations.</p>

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

15.01.0 ≤ v < publication15.02.0 ≤ v < publication15.01.015.02.020162016 cumulative_update_1820192019 cumulative_update_7
Affected range stops below publication, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

5.4MEDIUMmicrosoft
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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