CVE-2021-26887
Microsoft Windows Folder Redirection Elevation of Privilege Vulnerability
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>
INFO
Published Date :
March 11, 2021, 4:15 p.m.
Last Modified :
Dec. 29, 2023, 8:15 p.m.
Source :
[email protected]
Remotely Exploitable :
No
Impact Score :
5.9
Exploitability Score :
1.8
Public PoC/Exploit Available at Github
CVE-2021-26887 has a 4 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
Affected Products
The following products are affected by CVE-2021-26887
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-26887.
| URL | Resource |
|---|---|
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887 | Patch Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Internal penetration testing report.
Jason Abeiku Boateng Techie
Imoro Umar Farouq's report on Internal Network Penetration Testing
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-26887 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-26887 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Dec. 29, 2023
Action Type Old Value New Value Changed Description Microsoft Windows Folder Redirection Elevation of Privilege Vulnerability <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> Added CVSS V3.1 Microsoft Corporation AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
CWE Remap by [email protected]
May. 03, 2022
Action Type Old Value New Value Changed CWE CWE-269 CWE-59 -
Initial Analysis by [email protected]
Mar. 12, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:P/I:P/A:P) Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Changed Reference Type https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887 No Types Assigned https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887 Patch, Vendor Advisory Added CWE NIST CWE-269 Added CPE Configuration OR *cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:* *cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-26887 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-26887
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.08 }} 0.01%
score
0.36049
percentile