Vulnerability · NVD

CVE-2021-26887

CVE-2021-26887 : high severity (CVSS 7.8). No tracked catalog app is linked to this CVE.

Severity (CVSS): 7.8
Exploitation: 1.1 %
Tracked apps: 0
Still exposed: 0

Published on 2021-03-11

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.

Attack vector : Local No user interaction

Show raw CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS 1.06% above median percentile 63.0%

OS versions that fix this CVE

This CVE is resolved by the following OS security releases. Update the OS to at least the listed version.

Windows Server 2019 (Server Core installation) Fixed in -
Windows Server 2019 Fixed in -
Windows Server 2016 (Server Core installation) Fixed in -
Windows Server 2016 Fixed in -
Windows 10 20H2 · 2020-H2 Fixed in -
Windows 10 2004 · 2020-04 Fixed in -
Windows 10 1909 · 2019-09 Fixed in -
Windows 10 1809 · 2018-09 Fixed in -
Windows 10 1803 · 2018-03 Fixed in -
Windows 10 1607 · 2016-07 Fixed in -

View on NVD ↗ Advisory · portal.msrc.microsoft.com

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