CVE-2021-26887

7.8 HIGH
Published: March 11, 2021 Modified: February 24, 2026
View on NVD

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>

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Vendor Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.8 / 10.0
EPSS (Exploit Probability)
0.5%
64th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

microsoft