CVE-2017-11775 in SharePoint Enterprise Server
Summary
by MITRE
Microsoft SharePoint Enterprise Server 2013 SP1 and Microsoft SharePoint Enterprise Server 2016 allow an attacker to exploit a cross-site scripting (XSS) vulnerability by sending a specially crafted request to an affected SharePoint server, due to how SharePoint Server sanitizes web requests, aka "Microsoft Office SharePoint XSS Vulnerability". This CVE ID is unique from CVE-2017-11777 and CVE-2017-11820.
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Analysis
by VulDB Data Team • 01/16/2021
The vulnerability identified as CVE-2017-11775 represents a critical cross-site scripting flaw within Microsoft SharePoint Enterprise Server versions 2013 SP1 and 2016. This security weakness stems from insufficient sanitization of web requests within the SharePoint server infrastructure, creating an exploitable condition that allows remote attackers to inject malicious scripts into web pages viewed by other users. The vulnerability specifically affects the server-side request processing mechanisms that are responsible for filtering and validating user input before rendering content, which creates a pathway for attackers to bypass existing security controls.
The technical implementation of this vulnerability occurs when SharePoint Server fails to adequately sanitize user-supplied input in web requests, particularly in contexts where dynamic content is generated or displayed. Attackers can craft malicious requests containing script code that gets processed and subsequently executed in the browser context of legitimate users who access the affected SharePoint sites. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications. The vulnerability's exploitation relies on the server's inadequate validation and sanitization of input parameters, allowing malicious payloads to persist and execute within the user's browser session.
The operational impact of CVE-2017-11775 extends beyond simple script execution, as it can enable attackers to perform a range of malicious activities including session hijacking, credential theft, and redirection to malicious websites. When exploited successfully, the vulnerability allows attackers to execute arbitrary code within the context of the victim's browser, potentially leading to full compromise of user sessions and access to sensitive corporate data. The attack surface is particularly concerning in enterprise environments where SharePoint servers often contain confidential business information, employee data, and internal communications that could be accessed through successful exploitation of this XSS vulnerability.
Organizations affected by this vulnerability should implement immediate mitigations including applying the relevant Microsoft security patches released in the July 2017 security updates, which specifically address the XSS sanitization issues within SharePoint Server. Network administrators should also consider implementing additional protective measures such as web application firewalls that can detect and block malicious script payloads, along with enhanced input validation mechanisms at the application level. The vulnerability's classification under the ATT&CK framework would place it within the Tactic of Execution and the Technique of Command and Scripting Interpreter, as attackers can leverage this weakness to execute malicious code in user browsers. Organizations should also conduct comprehensive security assessments of their SharePoint environments to identify any additional vulnerabilities that could be exploited in conjunction with this XSS flaw.