CVE-2021-28326: Microsoft Windows AppX Deployment Service Directory Junction Denial-of-Service Vulnerability

Published Apr 13, 2021
·
Updated

Windows AppX Deployment Server Denial of Service Vulnerability

Other sources

This vulnerability allows local attackers to create a denial-of-service condition on affected installations of Microsoft Windows. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the AppX Deployment Service. By creating a directory junction, an attacker can abuse the service to delete the contents of a chosen directory. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.

ZDI

Affected Software

39 affected componentsFixes available
Microsoft Windows Server=2004
Microsoft Windows Server=20H2
Microsoft Windows Server=1909
Microsoft Windows Server 2016
Microsoft Windows Server 2016
Microsoft Windows Server 2019
Microsoft Windows Server 2019
Microsoft Windows 10=20H2
Microsoft Windows 10=20H2
Microsoft Windows 10=20H2
Microsoft Windows 10=1803
Microsoft Windows 10=1809
Microsoft Windows 10=1809
Microsoft Windows 10=1809
Microsoft Windows 10=1607
Microsoft Windows 10=1607
Microsoft Windows 10=1909
Microsoft Windows 10=1909
Microsoft Windows 10=1909
Microsoft Windows 10
Microsoft Windows 10=1803
Microsoft Windows 10=1803
Microsoft Windows 10
Microsoft Windows 10=2004
Microsoft Windows 10=2004
Microsoft Windows 10=2004
Microsoft Windows 10
Microsoft Windows 10=20h2
Microsoft Windows 10=1607
Microsoft Windows 10=1803
Microsoft Windows 10=1809
Microsoft Windows 10=1909
Microsoft Windows 10=2004
Microsoft Windows Server 2016
Microsoft Windows Server 2016=20h2
Microsoft Windows Server 2016=1909
Microsoft Windows Server 2016=2004
Microsoft Windows Server 2019
Microsoft Windows

Event History

Apr 13, 2021
CVE Published
via Microsoft·07:00 AM
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeakness
CVE Published
via MITRE·07:32 PM
Data Sourced
via MITRE·07:32 PM
DescriptionSeverity
Apr 1, 2025
Advisory Published
via ZDI·05:16 PM

Frequently Asked Questions

1

What is the severity of CVE-2021-28326?

CVE-2021-28326 has a severity rating of Critical as it allows local attackers to create a denial-of-service condition.

2

How do I fix CVE-2021-28326?

To fix CVE-2021-28326, apply the relevant security updates provided by Microsoft for affected Windows versions.

3

Which systems are affected by CVE-2021-28326?

CVE-2021-28326 affects multiple versions of Windows 10 and Windows Server, specifically the 20H2, 1803, 1809, 1909, and 2004 releases.

4

Can CVE-2021-28326 be exploited remotely?

CVE-2021-28326 requires local access to exploit, making it not applicable to remote attack scenarios.

5

How does CVE-2021-28326 affect system availability?

CVE-2021-28326 can be used by attackers to cause a denial-of-service condition, rendering the affected application temporarily unavailable.

Contact

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