CVE-2020-0694 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-2020-0693.
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Analysis
by VulDB Data Team • 05/12/2025
The CVE-2020-0694 vulnerability represents a critical cross-site scripting flaw in Microsoft SharePoint Server that enables attackers to execute malicious scripts in the context of a victim's browser session. This vulnerability specifically arises from the improper sanitization of web requests processed by SharePoint Server, creating an attack vector that can be exploited through crafted malicious inputs. The flaw affects multiple versions of Microsoft SharePoint Server including SharePoint Server 2016 and SharePoint Server 2019, making it a widespread concern for organizations utilizing these platforms. The vulnerability is particularly dangerous because it allows attackers to inject malicious code that can persist on the server and affect multiple users who interact with the vulnerable SharePoint instance.
This XSS vulnerability stems from the server's insufficient input validation and output encoding mechanisms when processing web requests containing specially crafted payloads. The affected SharePoint Server fails to properly sanitize user-supplied input data, particularly in areas where web requests are processed and rendered back to users. The flaw manifests when SharePoint Server receives web requests that contain malicious script code which is then improperly handled during the rendering process, allowing the injected scripts to execute in the context of legitimate user sessions. This type of vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting flaws in software applications. The vulnerability's classification as a server-side XSS issue means that the malicious code injection occurs on the server rather than client-side, potentially allowing for more persistent and dangerous attacks.
The operational impact of CVE-2020-0694 extends far beyond simple script execution, as successful exploitation can lead to complete session hijacking, data theft, and privilege escalation within the SharePoint environment. Attackers can leverage this vulnerability to steal authentication cookies, access sensitive documents and data, and potentially gain administrative privileges if the victim is a privileged user. The persistent nature of the vulnerability means that once exploited, malicious scripts can continue to affect users until the vulnerability is patched or the server is properly sanitized. Organizations running SharePoint Server are at risk of unauthorized access to confidential information, potential data breaches, and the compromise of internal network resources. This vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, as attackers can use the XSS flaw to execute malicious scripts and establish persistent access. The vulnerability also maps to ATT&CK technique T1566.001 for Phishing, as attackers can craft malicious SharePoint pages to trick users into executing the malicious code.
Mitigation strategies for CVE-2020-0694 require immediate action including applying Microsoft security patches and updates released in their monthly security updates. Organizations should implement comprehensive input validation and output encoding mechanisms to prevent malicious script injection, particularly in areas where user input is processed and displayed. Network segmentation and access controls should be strengthened to limit the impact of potential exploitation, while security monitoring systems should be enhanced to detect anomalous requests and script execution patterns. Regular security assessments and penetration testing of SharePoint environments can help identify additional vulnerabilities that may compound the risks associated with this XSS flaw. Administrators should also consider implementing web application firewalls and content security policies to provide additional layers of protection against script injection attacks. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and proper input sanitization in enterprise web applications, as even minor oversights in code validation can lead to severe security breaches. Organizations should also conduct regular security awareness training for administrators and users to recognize potential phishing attempts that may exploit this vulnerability.