CVE-2021-26887

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 users 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.

Risk Information

Base Score

7.7

MODERATE

Vector

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

EPSS Score

Exploitation Probability

0.459

Associated Vulnerability

Vulnerability	OS Platform
User Profile Service Denial of Service Vulnerability for Windows Server 2012 for x64-based Systems (KB5000840)	Windows
User Profile Service Denial of Service Vulnerability for Windows Server 2012 for x64-based Systems (KB5000847)	Windows

Patch Details

Click to see the patches provided by ManageEngine for this CVE

Patch ID	Patch Description
PATCH-30948	2021-03 Security Only Quality Update for Windows Server 2012 for x64-based Systems (KB5000840)
PATCH-30961	2021-03 Security Monthly Quality Rollup for Windows Server 2012 for x64-based Systems (KB5000847) (CVE-2021-26411)

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234