Medium6.5Microsoft Server

Medium [CVE-2021-42305] Microsoft Exchange Server Spoofing Vulnerability

This medium-severity Microsoft Server advisory covers CVE-2021-42305 affecting Microsoft Exchange Server 2013 Cumulative Update 23, Microsoft Exchange Server 2016 Cumulative Update 21, Microsoft Exchange Server 2016 Cumulative Update 22.

CVE-2021-42305 Published Nov 10, 2021Updated by vendor Aug 19, 2026

CVE-2021-42305

Affected products & platforms

Microsoft ServerExchange Server

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Summary

Microsoft Exchange Server Spoofing Vulnerability

Affected products named by the advisory: Microsoft Exchange Server 2013 Cumulative Update 23; Microsoft Exchange Server 2016 Cumulative Update 21; Microsoft Exchange Server 2016 Cumulative Update 22; Microsoft Exchange Server 2019 Cumulative Update 10; and 1 more.

Affected products named by the advisory: Microsoft Exchange Server 2019 Cumulative Update 11.

Affected versions

Microsoft Exchange Server 2013 Cumulative Update 23 15.00.0 before 15.00.1497.026
Microsoft Exchange Server 2016 Cumulative Update 21 15.01.0 before 15.01.2308.020
Microsoft Exchange Server 2016 Cumulative Update 22 15.0.0 before 15.01.2375.017
Microsoft Exchange Server 2019 Cumulative Update 10 15.02.0 before 15.02.0792.019
Microsoft Exchange Server 2019 Cumulative Update 11 15.02.0 before 15.02.0986.014

Official advisory · high-confidence parse· fetched 2 hours ago·verify at source

Fixed versions

15.00.1497.026
15.01.2308.020
15.01.2375.017
15.02.0792.019
15.02.0986.014

Official advisory · high-confidence parse· fetched 2 hours ago·verify at source

Mitigation

Upgrade to a fixed release: 15.00.1497.026, 15.01.2308.020, 15.01.2375.017, 15.02.0792.019, 15.02.0986.014. That is the remediation for this advisory.

The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.

Official advisory · high-confidence parse· fetched 2 hours ago·verify at source

Discussion(0)

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