Description
An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder.
To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.
This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the FAQ section of this CVE for configuration guidance.
Published: 2021-03-11
Score: 7.8 High
EPSS: 1.1% Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2021-13671 <p>An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder.</p> <p>To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.</p> <p>This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p>
History

Wed, 19 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
Description <p>An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder.</p> <p>To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.</p> <p>This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p> An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder. To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data. This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the FAQ section of this CVE for configuration guidance.
First Time appeared Microsoft windows 10 1507
Microsoft windows 10 1607
Microsoft windows 10 1809
Microsoft windows 10 1909
Microsoft windows 10 20h2
Microsoft windows Server 1909
Microsoft windows Server 2004
Microsoft windows Server 2008 R2
Microsoft windows Server 2008 Sp2
Microsoft windows Server 2012 R2
Microsoft windows Server 20h2
CPEs cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_20H2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_7:*:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_7:*:sp1:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_8.1:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_server_1909:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008_R2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2008_sp2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_20H2:*:*:*:*:*:*:*:*
Vendors & Products Microsoft windows 10 1507
Microsoft windows 10 1607
Microsoft windows 10 1809
Microsoft windows 10 1909
Microsoft windows 10 20h2
Microsoft windows Server 1909
Microsoft windows Server 2004
Microsoft windows Server 2008 R2
Microsoft windows Server 2008 Sp2
Microsoft windows Server 2012 R2
Microsoft windows Server 20h2
References

Tue, 24 Feb 2026 16:15:00 +0000

Type Values Removed Values Added
Description <p>An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder.</p> <p>To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.</p> <p>This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p> <p>An elevation of privilege vulnerability exists in Microsoft Windows when Folder redirection has been enabled via Group Policy. When folder redirection file server is co-located with Terminal server, an attacker who successfully exploited the vulnerability would be able to begin redirecting another user's personal data to a created folder.</p> <p>To exploit the vulnerability, an attacker can create a new folder under the Folder Redirection root path and create a junction on a newly created User folder. When the new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.</p> <p>This elevation of privilege vulnerability can only be addressed by reconfiguring Folder Redirection with Offline files and restricting permissions, and NOT via a security update for affected Windows Servers. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p>

Tue, 19 Nov 2024 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Subscriptions

Microsoft Windows 10 Windows 10 1507 Windows 10 1607 Windows 10 1809 Windows 10 1909 Windows 10 20h2 Windows 7 Windows 8.1 Windows Rt 8.1 Windows Server 1909 Windows Server 2004 Windows Server 2008 Windows Server 2008 R2 Windows Server 2008 Sp2 Windows Server 2012 Windows Server 2012 R2 Windows Server 2016 Windows Server 2019 Windows Server 20h2
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2026-08-19T16:30:31.969Z

Reserved: 2021-02-08T00:00:00.000Z

Link: CVE-2021-26887

cve-icon Vulnrichment

Updated: 2024-08-03T20:33:41.285Z

cve-icon NVD

Status : Modified

Published: 2021-03-11T16:15:15.800

Modified: 2026-08-19T17:17:44.767

Link: CVE-2021-26887

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-59

    Improper Link Resolution Before File Access ('Link Following')