KB5000840: Windows Server 2012 March 2021 Security Update

critical Nessus Plugin ID 147221
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.


The remote Windows host is affected by multiple vulnerabilities.


The remote Windows host is missing security update 5000840 or cumulative update 5000847. It is, therefore, affected by multiple vulnerabilities :

- A remote code execution vulnerability. An attacker can exploit this to bypass authentication and execute unauthorized arbitrary commands. (CVE-2021-26861, CVE-2021-26877, CVE-2021-26881, CVE-2021-26893, CVE-2021-26894, CVE-2021-26895, CVE-2021-26897)

- An information disclosure vulnerability. An attacker can exploit this to disclose potentially sensitive information. (CVE-2021-24107, CVE-2021-26869, CVE-2021-26884)

- A denial of service (DoS) vulnerability. An attacker can exploit this issue to cause the affected component to deny system or application services. (CVE-2021-26886, CVE-2021-26896, CVE-2021-27063)

- An memory corruption vulnerability exists. An attacker can exploit this to corrupt the memory and cause unexpected behaviors within the system/application.

- An elevation of privilege vulnerability. An attacker can exploit this to gain elevated privileges.
(CVE-2021-1640, CVE-2021-26862, CVE-2021-26868, CVE-2021-26872, CVE-2021-26873, CVE-2021-26875, CVE-2021-26878, CVE-2021-26882, CVE-2021-26898, CVE-2021-26899, CVE-2021-26901)


Apply Security Only update KB5000840 or Cumulative Update KB5000847.

See Also



Plugin Details

Severity: Critical

ID: 147221

File Name: smb_nt_ms21_mar_5000847.nasl

Version: 1.8

Type: local

Agent: windows

Published: 3/9/2021

Updated: 11/30/2021

Dependencies: smb_check_rollup.nasl, smb_hotfixes.nasl, ms_bulletin_checks_possible.nasl

Risk Information

CVSS Score Source: CVE-2021-26861


Risk Factor: Critical

Score: 9.8


Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: E:H/RL:OF/RC:C


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.4

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:H/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:microsoft:windows

Required KB Items: SMB/MS_Bulletin_Checks/Possible

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/8/2021

Vulnerability Publication Date: 3/8/2021

Reference Information

CVE: CVE-2021-1640, CVE-2021-24107, CVE-2021-26411, CVE-2021-26861, CVE-2021-26862, CVE-2021-26868, CVE-2021-26869, CVE-2021-26872, CVE-2021-26873, CVE-2021-26875, CVE-2021-26877, CVE-2021-26878, CVE-2021-26881, CVE-2021-26882, CVE-2021-26884, CVE-2021-26886, CVE-2021-26893, CVE-2021-26894, CVE-2021-26895, CVE-2021-26896, CVE-2021-26897, CVE-2021-26898, CVE-2021-26899, CVE-2021-26901, CVE-2021-27063

MSKB: 5000847, 5000840

MSFT: MS21-5000847, MS21-5000840

IAVA: 2021-A-0130-S, 2021-A-0134-S