VDB-188247 · CVE-2021-43240 · WID-SEC-2025-2220

Microsoft Windows up to Server 2022 NTFS Set Short Name privilege escalation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.5	$5k-$25k	0.00

Summaryinfo

A vulnerability has been found in Microsoft Windows up to Server 2022 and classified as critical. This issue affects some unknown processing of the component NTFS Set Short Name. Performing a manipulation results in an unknown weakness. This vulnerability is reported as CVE-2021-43240. The attack is possible to be carried out remotely. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as critical, was found in Microsoft Windows up to Server 2022 (Operating System). This affects an unknown part of the component NTFS Set Short Name. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was disclosed 12/14/2021 as confirmed security guidance (Website). It is possible to read the advisory at portal.msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2021-43240. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/07/2025).

It is declared as proof-of-concept.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2220). Be aware that VulDB is the high quality source for vulnerability data.

Affected

Microsoft Windows 7 x64 Edition Service Pack 1
Microsoft Windows RT 8.1
Microsoft Windows 8.1 for x64-based Systems
Microsoft Windows 10
Microsoft Windows Server 2012
Microsoft Windows Server 2016
Hitachi Storage
Microsoft Windows Server 2008 Service Pack 2
Microsoft Windows Server 2008 R2
Microsoft Windows Server 2019
Microsoft Windows Server 2012 R2
Microsoft Windows Server
Microsoft Windows Server 2022
Microsoft Windows 11

Productinfo

Type

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

Vendor: https://www.microsoft.com/
Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 7.5

VulDB Base Score: 8.8
VulDB Temp Score: 7.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.8
Vendor Vector (Microsoft): 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

11/02/2021 🔍
12/14/2021 +42 days 🔍
12/14/2021 +0 days 🔍
12/15/2021 +0 days 🔍
10/07/2025 +1392 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: portal.msrc.microsoft.com
Status: Confirmed

CVE: CVE-2021-43240 (🔍)
GCVE (CVE): GCVE-0-2021-43240
GCVE (VulDB): GCVE-100-188247
CERT Bund: WID-SEC-2025-2220 - Microsoft Windows und Microsoft Windows Server: Mehrere Schwachstellen

scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 12/15/2021 06:04
Updated: 10/07/2025 16:26
Changes: 12/15/2021 06:04 (33), 12/15/2021 06:08 (21), 12/17/2021 14:44 (2), 10/07/2025 16:26 (22)
Complete: 🔍
Cache ID: 216::103