KLA11053 XSS vulnerabilities in Microsoft Sharepoint

Multiple serious vulnerabilities have been found in Microsoft Sharepoint. Malicious users can exploit these vulnerabilities to obtain sensitive information and gain privileges.

Below is a complete list of vulnerabilities:

1. An improper sanitizing of user web requests can be exploited remotely via a specially designed web request to obtain sensitive information;
2. An incorrect sanitizing of web requests can be exploited remotely via a specially designed web request to gain privileges.

Technical details

Vulnerability (1) can only be exploited if user clicks a specially designed URL which takes the user to a targeted Sharepoint Web App site. A malicious URL can be sent via email or it can be on a website hosted by a malicious user. In both cases the attacker should convince a user to click malicious URL.

Original advisories

CVE-2017-8514

CVE-2017-8551

Exploitation

Malware exists for this vulnerability. Usually such malware is classified as Exploit. More details.

Related products

Microsoft-Sharepoint-Server

CVE list

CVE-2017-8551 warning

CVE-2017-8514 warning

KB list

3203432

3203399

Solution

Install necessary updates from the KB section, that are listed in your Windows Update (Windows Update usually can be accessed from the Control Panel)

Impacts

• ACE

Arbitrary code execution. Exploitation of vulnerabilities with this impact can lead to executing by abuser any code or commands at vulnerable machine or process.

• OSI

Obtain sensitive information. Exploitation of vulnerabilities with this impact can lead to capturing by abuser information, critical for user or system.

• SB

Security bypass. Exploitation of vulnerabilities with this impact can lead to performing actions restricted by current security settings.

• PE

Privilege escalation. Exploitation of vulnerabilities with this impact can lead to performing by abuser actions, which are normally disallowed for current role.

• SUI

Spoof user interface. Exploitation of vulnerabilities with this impact can lead to changes in user interface to beguile user into inaccurate behavior.

Affected Products

• Microsoft SharePoint Enterprise Server 2016Microsoft Project Server 2013 Service Pack 1