Vulnerability CVE-2021-31961 - CERT Civis.Net

Vulnerability Name:

CVE-2021-31961 (CCN-204537)

Assigned:

2021-07-13

Published:

2021-07-13

Updated:

2021-09-20

Summary:

Windows InstallService Elevation of Privilege Vulnerability

CVSS v3 Severity:

6.1 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H)
5.3 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H/E:U/RL:O/RC:C)

Exploitability Metrics:	Attack Vector (AV): Local Attack Complexity (AC): Low Privileges Required (PR): Low User Interaction (UI): None
Scope:	Scope (S): Unchanged
Impact Metrics:	Confidentiality (C): None Integrity (I): Low Availibility (A): High

6.1 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H)
5.3 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H/E:U/RL:O/RC:C)

Exploitability Metrics:	Attack Vector (AV): Local Attack Complexity (AC): Low Privileges Required (PR): Low User Interaction (UI): None
Scope:	Scope (S): Unchanged
Impact Metrics:	Confidentiality (C): None Integrity (I): Low Availibility (A): High

CVSS v2 Severity:

3.6 Low (CVSS v2 Vector: AV:L/AC:L/Au:N/C:N/I:P/A:P)

Exploitability Metrics:	Access Vector (AV): Local Access Complexity (AC): Low Authentication (Au): None
Impact Metrics:	Confidentiality (C): None Integrity (I): Partial Availibility (A): Partial

5.2 Medium (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:N/I:P/A:C)

Exploitability Metrics:	Access Vector (AV): Local Access Complexity (AC): Low Athentication (Au): Single_Instance
Impact Metrics:	Confidentiality (C): None Integrity (I): Partial Availibility (A): Complete

Vulnerability Type:

Vulnerability Consequences:

Gain Privileges

References:

Source: MITRE
Type: CNA
CVE-2021-31961

Source: XF
Type: UNKNOWN
ms-windows-cve202131961-priv-esc(204537)

Source: CCN
Type: Microsoft Security TechCenter - July 2021
Windows InstallService Elevation of Privilege Vulnerability

Source: MISC
Type: Patch, Vendor Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31961

Source: CCN
Type: ZDI-21-818
Microsoft Windows InstallService Time-Of-Check Time-Of-Use Denial-of-Service Vulnerability

Source: MISC
Type: Third Party Advisory, VDB Entry
https://www.zerodayinitiative.com/advisories/ZDI-21-818/

Vulnerable Configuration:

Configuration 1:

cpe:/o:microsoft:windows_10:20h2:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:21h1:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:1809:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:1909:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:2004:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_server_20h2:-:*:*:*:*:*:x64:*

OR cpe:/o:microsoft:windows_server_2004:-:*:*:*:*:*:x64:*

OR cpe:/o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*

Configuration CCN 1:

cpe:/o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:1809::~~~~x64~:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:1809:*:*:*:*:*:x32:*

OR cpe:/o:microsoft:windows_10_1809:-:*:*:*:*:*:arm64:*

OR cpe:/o:microsoft:windows_10:2004:*:*:*:*:*:x32:*

OR cpe:/o:microsoft:windows_10_2004:-:*:*:*:*:*:arm64:*

OR cpe:/o:microsoft:windows_10_2004:-:*:*:*:*:*:x64:*

OR cpe:/o:microsoft:windows_10:1909:*:*:*:*:*:x32:*

OR cpe:/o:microsoft:windows_10_1909:-:*:*:*:*:*:x64:*

OR cpe:/o:microsoft:windows_10_1909:-:*:*:*:*:*:arm64:*

OR cpe:/o:microsoft:windows_10:20h2:*:*:*:*:*:x32:*

OR cpe:/o:microsoft:windows_10_20h2:-:*:*:*:*:*:arm64:*

OR cpe:/o:microsoft:windows_10_20h2:-:*:*:*:*:*:x64:*

OR cpe:/o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_server:2004:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_server:20h2:*:*:*:*:*:*:*

OR cpe:/o:microsoft:windows_10:21h1:*:*:*:*:*:x32:*

OR cpe:/o:microsoft:windows_10_21h1:-:*:*:*:*:*:arm64:*

OR cpe:/o:microsoft:windows_10_21h1:-:*:*:*:*:*:x64:*

Denotes that component is vulnerable