Security Updates for Microsoft Skype for Business and Microsoft Lync and Microsoft Live Meeting (September 2017)
Critical Nessus Plugin ID 103123
SynopsisThe Microsoft Skype for Business or Microsoft Lync or Microsoft Live Meeting installation on the remote host is affected by multiple vulnerabilities.
DescriptionThe Microsoft Skype for Business or Microsoft Lync or Microsoft Live Meeting installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities :
- An information disclosure vulnerability exists when Windows Uniscribe improperly discloses the contents of its memory. An attacker who successfully exploited the vulnerability could obtain information to further compromise the users system. There are multiple ways an attacker could exploit the vulnerability, such as by convincing a user to open a specially crafted document or by convincing a user to visit an untrusted webpage.
The update addresses the vulnerability by correcting how Windows Uniscribe handles objects in memory.
- An information disclosure vulnerability exists in the way that the Windows Graphics Device Interface (GDI) handles objects in memory, allowing an attacker to retrieve information from a targeted system. By itself, the information disclosure does not allow arbitrary code execution; however, it could allow arbitrary code to be run if the attacker uses it in combination with another vulnerability. To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted application. Note that where the severity is indicated as Critical in the Affected Products table, the Preview Pane is an attack vector for this vulnerability. The security update addresses the vulnerability by correcting how GDI handles memory addresses. (CVE-2017-8676)
- A remote code execution vulnerability exists due to the way Windows Uniscribe handles objects in memory. An attacker who successfully exploited this vulnerability could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. There are multiple ways an attacker could exploit this vulnerability: In a web-based attack scenario, an attacker could host a specially crafted website designed to exploit this vulnerability and then convince a user to view the website. An attacker would have no way to force users to view the attacker-controlled content.
Instead, an attacker would have to convince users to take action, typically by getting them to click a link in an email or instant message that takes users to the attacker's website, or by opening an attachment sent through email. In a file-sharing attack scenario, an attacker could provide a specially crafted document file designed to exploit this vulnerability and then convince a user to open the document file.The security update addresses the vulnerability by correcting how Windows Uniscribe handles objects in memory. (CVE-2017-8696)
SolutionMicrosoft has released the following security updates to address this issue: