CVE-2020-1107 in SharePoint Enterprise Server
Summary
by MITRE
A spoofing vulnerability exists when Microsoft SharePoint Server does not properly sanitize a specially crafted web request to an affected SharePoint server, aka 'Microsoft SharePoint Spoofing Vulnerability'. This CVE ID is unique from CVE-2020-1104, CVE-2020-1105.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability identified as CVE-2020-1107 represents a critical spoofing weakness within Microsoft SharePoint Server that arises from inadequate input sanitization mechanisms. This flaw specifically manifests when the affected server fails to properly validate and sanitize web requests containing maliciously crafted content, creating opportunities for attackers to manipulate server behavior through carefully constructed HTTP requests. The vulnerability resides in the server's request processing pipeline where insufficient validation allows crafted payloads to bypass normal security controls and potentially alter expected server responses. This issue affects multiple versions of SharePoint Server and demonstrates a fundamental weakness in the application's handling of user-supplied data within web request contexts.
The technical implementation of this vulnerability stems from the server's failure to adequately sanitize user input within HTTP request parameters, headers, or body content. When SharePoint Server receives a specially crafted web request, the insufficient sanitization allows malicious data to propagate through the application layer without proper validation checks. This weakness can be exploited to manipulate server responses, potentially redirecting users to malicious sites or altering the presentation of content in ways that deceive users into believing they are interacting with legitimate SharePoint resources. The vulnerability operates at the application layer and can be triggered through standard HTTP methods such as GET, POST, or other request types that the SharePoint server accepts and processes.
From an operational impact perspective, this vulnerability creates significant risks for organizations relying on SharePoint Server for collaboration and document management services. Attackers could leverage this weakness to perform man-in-the-middle attacks by spoofing legitimate SharePoint resources, potentially leading to credential theft, data exfiltration, or further exploitation of the compromised environment. The vulnerability's impact extends beyond simple content manipulation as it can be combined with other attack vectors to create more sophisticated threats. Organizations may experience loss of user trust, regulatory compliance violations, and potential business disruption when attackers successfully exploit this weakness to compromise SharePoint environments. The attack surface is particularly concerning given SharePoint's widespread use in enterprise environments where sensitive data is frequently stored and shared.
Security mitigations for CVE-2020-1107 should focus on implementing robust input validation and sanitization controls within SharePoint Server configurations. Microsoft recommends applying the official security patches and updates released to address this vulnerability, which typically include enhanced validation mechanisms and improved request processing controls. Organizations should also implement network-level protections such as web application firewalls that can detect and block suspicious request patterns, while maintaining strict monitoring of SharePoint server logs for anomalous request behaviors. Additional defensive measures include implementing proper access controls, regularly auditing SharePoint configurations, and establishing incident response procedures specifically designed to address spoofing attacks. The vulnerability aligns with CWE-79 which addresses cross-site scripting and input validation issues, and may be categorized under ATT&CK technique T1566 for spearphishing with attachments, as attackers could potentially use this weakness to craft deceptive SharePoint pages that appear legitimate to users.