Security Updates for Microsoft Office Web Apps (July 2020)

high Nessus Plugin ID 138469
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 multiple vulnerabilities :

- An information disclosure vulnerability exists when Microsoft Office improperly discloses the contents of its memory. An attacker who exploited the vulnerability could use the information to compromise the users computer or data. (CVE-2020-1445)

- A remote code execution vulnerability exists in Microsoft Word software when it fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could use a specially crafted file to perform actions in the security context of the current user. For example, the file could then take actions on behalf of the logged-on user with the same permissions as the current user. (CVE-2020-1446, CVE-2020-1447, CVE-2020-1448)

- A spoofing vulnerability exists when an Office Web Apps server does not properly sanitize a specially crafted request. An authenticated attacker could exploit the vulnerability by sending a specially crafted request to an affected Office Web Apps server. The attacker who successfully exploited this vulnerability could then perform cross-site scripting attacks on affected systems and run script in the security context of the current user. For the vulnerability to be exploited, a user must click a specially crafted URL that takes the user to a targeted Office Web App site. (CVE-2020-1442)

- An information disclosure vulnerability exists when Microsoft Office software reads out of bound memory due to an uninitialized variable, which could disclose the contents of memory. An attacker who successfully exploited the vulnerability could view out of bound memory. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Office software. The security update addresses the vulnerability by properly initializing the affected variable. (CVE-2020-1342)

Solution

Microsoft has released the following security updates to address this issue:
-KB4484357
-KB4484381
-KB4484451

See Also

http://www.nessus.org/u?1ce2dd72

http://www.nessus.org/u?42ba0628

http://www.nessus.org/u?cce850ff

Plugin Details

Severity: High

ID: 138469

File Name: smb_nt_ms20_jul_office_web.nasl

Version: 1.5

Type: local

Agent: windows

Published: 7/14/2020

Updated: 8/14/2020

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-2020-1448

VPR

Risk Factor: Medium

Score: 6.7

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: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/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: 7/14/2020

Vulnerability Publication Date: 7/14/2020

Reference Information

CVE: CVE-2020-1342, CVE-2020-1442, CVE-2020-1445, CVE-2020-1446, CVE-2020-1447, CVE-2020-1448

MSKB: 4484357, 4484381, 4484451

MSFT: MS20-4484357, MS20-4484381, MS20-4484451

IAVA: 2020-A-0307-S