KB5000856: Windows Server 2008 March 2021 Security Update

critical Nessus Plugin ID 147217


The remote Windows host is affected by multiple vulnerabilities.


The remote Windows host is missing security update 5000856 or cumulative update 5000844. 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-2021-26893, CVE-2021-26894, CVE-2021-26895, CVE-2021-26897)

- An elevation of privilege vulnerability. An attacker can exploit this to gain elevated privileges.
(CVE-2021-1640, CVE-2021-26862, CVE-2021-26872, CVE-2021-26873, CVE-2021-26875, CVE-2021-26878, CVE-2021-26882, CVE-2021-26898, CVE-2021-26899, CVE-2021-26901, CVE-2021-27077)

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

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

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


Apply Security Only update KB5000856 or Cumulative Update KB5000844.

See Also



Plugin Details

Severity: Critical

ID: 147217

File Name: smb_nt_ms21_mar_5000844.nasl

Version: 1.12

Type: local

Agent: windows

Published: 3/9/2021

Updated: 12/5/2022

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent

Risk Information


Risk Factor: Critical

Score: 9.8


Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2021-26897


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: CVSS:3.0/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

CISA Known Exploited Dates: 11/17/2021

Exploitable With


Reference Information

CVE: CVE-2021-1640, CVE-2021-24107, CVE-2021-26411, CVE-2021-26861, CVE-2021-26862, CVE-2021-26872, CVE-2021-26873, CVE-2021-26875, CVE-2021-26877, CVE-2021-26878, CVE-2021-26882, 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, CVE-2021-27077

MSKB: 5000844, 5000856

MSFT: MS21-5000844, MS21-5000856

IAVA: 2021-A-0130-S, 2021-A-0134-S, 2021-A-0131-S