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.


The Microsoft Skype for Business installation on the remote host is missing a security update.


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.


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

See Also

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


Risk Factor: Medium

Score: 5.9


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


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