CVE-2021-31956 : Windows NTFS Elevation of Privilege Vulnerability

Products affected by CVE-2021-31956

Microsoft » Windows Server 2008 » Version: R2 Update SP1 For X64
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
Matching versions
Microsoft » Windows Server 2008 » Version: SP2
cpe:2.3:o:microsoft:windows_server_2008:sp2:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 7 » Version: N/A Update SP1
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
Matching versions
Microsoft » Windows Server 2012 » Version: N/A
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows Server 2012 » Version: R2
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 8.1 » Version: N/A
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows Rt 8.1 » Version: N/A
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 » Version: 1809
cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows Server 2016
Versions before (<) 10.0.14393.4467
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows Server 2019
Versions before (<) 10.0.17763.1999
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows Server 2004
Versions before (<) 10.0.19041.1052
cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 1607
Versions before (<) 10.0.14393.4467
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 21h1
Versions before (<) 10.0.19043.1052
cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 1809
Versions before (<) 10.0.17763.1999
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 20h2
Versions before (<) 10.0.19042.1052
cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 1507
Versions before (<) 10.0.10240.18967
cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 1909
Versions before (<) 10.0.18363.1621
cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows 10 2004
Versions before (<) 10.0.19041.1052
cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*
Matching versions
Microsoft » Windows Server 20h2
Versions before (<) 10.0.19042.1052
cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*
Matching versions

CVE-2021-31956 is in the CISA Known Exploited Vulnerabilities Catalog

CISA vulnerability name:

Microsoft Windows NTFS Privilege Escalation Vulnerability

CISA required action:

Apply updates per vendor instructions.

CISA description:

Microsoft Windows New Technology File System (NTFS) contains an unspecified vulnerability that allows attackers to escalate privileges via a specially crafted application.

Notes:

https://nvd.nist.gov/vuln/detail/CVE-2021-31956

Added on 2021-11-03 Action due date 2021-11-17

Exploit prediction scoring system (EPSS) score for CVE-2021-31956

EPSS FAQ

1.78%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 88 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-31956

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source	First Seen
9.3	HIGH	AV:N/AC:M/Au:N/C:C/I:C/A:C	8.6	10.0	NIST
Access Vector: Network Access Complexity: Medium Authentication: None Confidentiality Impact: Complete Integrity Impact: Complete Availability Impact: Complete
7.8	HIGH	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	1.8	5.9	NIST	2024-07-29
Attack Vector: Local Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High
7.8	HIGH	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	1.8	5.9	NIST
Attack Vector: Local Attack Complexity: Low Privileges Required: None User Interaction: Required Scope: Unchanged Confidentiality: High Integrity: High Availability: High
7.8	HIGH	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	1.8	5.9	Microsoft Corporation
Attack Vector: Local Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High

CWE ids for CVE-2021-31956

CWE-191 Integer Underflow (Wrap or Wraparound)

The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2021-31956