Security Updates for Microsoft Office Web Apps (July 2021)

high Nessus Plugin ID 151608
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.

Synopsis

The Microsoft Office Web Apps installation on the remote host is affected by multiple vulnerabilities.

Description

The Microsoft Office Web Apps installation on the remote host is missing security updates. It is, therefore, affected by the following vulnerabilities:

- Multiple remote code execution vulnerabilities in Microsoft Excel. (CVE-2021-34501, CVE-2021-34518)

- A spoofing vulnerability in Microsoft Office Online Server. (CVE-2021-34451).

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Microsoft has released the following security updates to address this issue:
-KB5001973
-KB5001986

See Also

http://www.nessus.org/u?8597074a

http://www.nessus.org/u?9c71158d

Plugin Details

Severity: High

ID: 151608

File Name: smb_nt_ms21_jul_office_web.nasl

Version: 1.4

Type: local

Agent: windows

Published: 7/13/2021

Updated: 9/16/2021

Dependencies: office_installed.nasl, microsoft_owa_installed.nbin, microsoft_office_compatibility_pack_installed.nbin, smb_hotfixes.nasl, ms_bulletin_checks_possible.nasl

Risk Information

CVSS Score Source: CVE-2021-34518

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

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

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

Vulnerability Information

CPE: cpe:/a:microsoft:office_web_apps

Required KB Items: SMB/MS_Bulletin_Checks/Possible

Exploit Ease: No known exploits are available

Patch Publication Date: 7/13/2021

Vulnerability Publication Date: 7/13/2021

Reference Information

CVE: CVE-2021-34451, CVE-2021-34501, CVE-2021-34518

MSKB: 5001973, 5001986

MSFT: MS21-5001973, MS21-5001986

IAVA: 2021-A-0316-S