Critical [CVE-2021-34523] Microsoft Exchange Server Elevation of Privilege Vulnerability
This critical-severity Microsoft Server advisory covers CVE-2021-34523 affecting Microsoft Exchange Server 2013 Cumulative Update 23, Microsoft Exchange Server 2016 Cumulative Update 19, Microsoft Exchange Server 2016 Cumulative Update 20.
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Summary
Microsoft Exchange Server Elevation of Privilege Vulnerability
Affected products named by the advisory: Microsoft Exchange Server 2013 Cumulative Update 23; Microsoft Exchange Server 2016 Cumulative Update 19; Microsoft Exchange Server 2016 Cumulative Update 20; Microsoft Exchange Server 2019 Cumulative Update 8; and 1 more.
Affected products named by the advisory: Microsoft Exchange Server 2019 Cumulative Update 9.
CISA Known Exploited Vulnerability
- Listed:
- Nov 3, 2021 · federal remediation due Nov 17, 2021
- Required action:
- Apply updates per vendor instructions.
- Ransomware use:
- Known
KEV is a prioritization signal from CISA — remediation detail still comes from the vendor advisory.
- Microsoft Exchange Server 2013 Cumulative Update 23 15.00.0 before 15.00.1497.015
- Microsoft Exchange Server 2016 Cumulative Update 19 15.01.0 before 15.01.2176.012
- Microsoft Exchange Server 2016 Cumulative Update 20 15.01.0 before 15.01.2242.008
- Microsoft Exchange Server 2019 Cumulative Update 8 15.02.0 before 15.02.0792.013
- Microsoft Exchange Server 2019 Cumulative Update 9 15.02.0 before 15.02.0858.010
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
- 15.00.1497.015
- 15.01.2176.012
- 15.01.2242.008
- 15.02.0792.013
- 15.02.0858.010
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Mitigation
Upgrade to a fixed release: 15.00.1497.015, 15.01.2176.012, 15.01.2242.008, 15.02.0792.013, 15.02.0858.010. 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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