Security Updates for Microsoft Skype for Business (July 2020)

critical Nessus Plugin ID 139314
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 Skype for Business installation on the remote host is missing a security update.

Description

The Microsoft Skype for Business installation on the remote host is missing a security update. It is, therefore, affected by the following vulnerability :

- An elevation of privilege vulnerability exists when Microsoft SharePoint Server and Skype for Business Server improperly handle OAuth token validation. An attacker who successfully exploited the vulnerability could bypass authentication and achieve improper access.
(CVE-2020-1025)

Solution

Microsoft has released the following security updates to address this issue:
-KB4571332
-KB4571333
-KB4571334

See Also

http://www.nessus.org/u?6a64541d

http://www.nessus.org/u?5e36ad5f

http://www.nessus.org/u?b2c18bf1

Plugin Details

Severity: Critical

ID: 139314

File Name: smb_nt_ms20_jul_skype.nasl

Version: 1.2

Type: local

Agent: windows

Published: 8/4/2020

Updated: 8/5/2020

Dependencies: office_installed.nasl, microsoft_lync_server_installed.nasl, smb_hotfixes.nasl, ms_bulletin_checks_possible.nasl

Risk Information

CVSS Score Source: CVE-2020-1025

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

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

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

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

Vulnerability Information

CPE: cpe:/a:microsoft:skype_for_business

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-2020-1025

MSKB: 4571332, 4571333, 4571334

MSFT: MS20-4571332, MS20-4571333, MS20-4571334