CVE-2020-0693 in SharePoint Enterprise Server
Summary
by MITRE
A cross-site-scripting (XSS) vulnerability exists when Microsoft SharePoint Server does not properly sanitize a specially crafted web request to an affected SharePoint server, aka 'Microsoft Office SharePoint XSS Vulnerability'. This CVE ID is unique from CVE-2020-0694.
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Analysis
by VulDB Data Team • 05/12/2025
The vulnerability identified as CVE-2020-0693 represents a critical cross-site scripting flaw within Microsoft SharePoint Server that allows attackers to execute malicious scripts in the context of affected users' browsers. This weakness stems from the server's insufficient sanitization of web requests containing crafted malicious input, creating an avenue for persistent code injection attacks that can compromise user sessions and data integrity. The vulnerability specifically affects Microsoft Office SharePoint Server implementations and has been classified under the CWE-79 category, which encompasses cross-site scripting vulnerabilities that occur when untrusted data is improperly integrated into web pages served to users. The flaw enables attackers to inject malicious scripts that can execute in the victim's browser environment, potentially leading to session hijacking, data theft, or further exploitation of the compromised system.
The technical exploitation of this vulnerability occurs when SharePoint Server fails to adequately validate and sanitize user input received through web requests, particularly in parameters that are directly rendered in web page content without proper encoding or filtering mechanisms. Attackers can craft malicious URLs or form submissions that contain script payloads which, when processed by the vulnerable SharePoint server, get executed in the browser of any user who views the affected page or interacts with the malicious content. The vulnerability's impact is amplified by SharePoint Server's role as a collaboration platform where users frequently access and interact with various web-based content, making it a prime target for persistent XSS attacks. This type of vulnerability falls under the ATT&CK technique T1059.001 for Command and Scripting Interpreter, specifically focusing on script-based attacks that leverage web application vulnerabilities to execute malicious code in user browsers.
The operational impact of CVE-2020-0693 extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including credential theft through session hijacking, data exfiltration from authenticated user sessions, and potential lateral movement within the network. The vulnerability's presence in SharePoint Server creates persistent attack vectors that can be exploited across multiple user sessions and interactions, making it particularly dangerous for organizations that rely heavily on SharePoint for document management, collaboration, and enterprise content sharing. Organizations with SharePoint deployments are at risk of unauthorized access to sensitive corporate data, as attackers can leverage this vulnerability to establish persistent access to user accounts and potentially gain elevated privileges within the SharePoint environment. The vulnerability's exploitation requires minimal technical expertise and can be automated, making it attractive to threat actors seeking to compromise SharePoint environments at scale.
Mitigation strategies for CVE-2020-0693 should prioritize immediate patch application from Microsoft as the primary defense mechanism, alongside comprehensive input validation and output encoding implementations. Organizations should implement robust web application firewalls and content security policies that can detect and block malicious script payloads before they reach vulnerable SharePoint instances. The implementation of proper HTML encoding and context-aware output sanitization mechanisms can significantly reduce the attack surface for XSS vulnerabilities. Security teams should also establish monitoring procedures to detect anomalous user behavior or unexpected script execution patterns within SharePoint environments. Additional defensive measures include restricting user privileges, implementing multi-factor authentication, and conducting regular security assessments of SharePoint configurations. The vulnerability underscores the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that include both perimeter security controls and internal application-level protections to prevent successful exploitation of web-based vulnerabilities.