CVE-2020-17089 in SharePoint
Summary
by MITRE • 12/10/2020
, aka 'Microsoft SharePoint Elevation of Privilege Vulnerability'.
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Analysis
by VulDB Data Team • 08/29/2025
This vulnerability represents a critical elevation of privilege flaw in Microsoft SharePoint Server that allows authenticated attackers to escalate their privileges within the system. The vulnerability specifically affects SharePoint Server 2016 and SharePoint Server 2019 installations, where an authenticated user with limited permissions can potentially gain access to administrative privileges through a flaw in the permission checking mechanisms. The issue stems from improper validation of user permissions during certain administrative operations, creating a pathway for privilege escalation that violates fundamental security principles of least privilege and access control.
The technical root cause of CVE-2020-17089 lies in the SharePoint Server's handling of permission validation within its administrative interfaces. When users perform specific operations within SharePoint, the system should verify that the requesting user possesses the necessary administrative rights before granting access to sensitive functions. However, a flaw exists in this validation process that allows users with lower privilege levels to bypass these checks and execute administrative commands. This type of vulnerability maps directly to CWE-284 which describes improper access control, and specifically relates to the broader category of privilege escalation vulnerabilities that undermine system security boundaries.
The operational impact of this vulnerability is significant as it can lead to complete system compromise when exploited by malicious actors. An attacker who has gained initial access to a SharePoint environment through other means can leverage this vulnerability to elevate their privileges and gain full administrative control over the SharePoint farm. This access enables the attacker to modify or delete content, manipulate user permissions, access sensitive data, and potentially use the compromised SharePoint server as a pivot point to attack other systems within the network. The vulnerability affects organizations that rely on SharePoint for collaboration and document management, making it particularly dangerous in enterprise environments where SharePoint often serves as a central hub for business-critical information.
Organizations should implement immediate mitigations including applying the relevant Microsoft security patches released in the July 2020 security updates. Additionally, network segmentation and monitoring should be enhanced to detect unusual administrative activities that might indicate exploitation attempts. Security teams should review and tighten permission policies within SharePoint environments, ensuring that the principle of least privilege is strictly enforced. The vulnerability also highlights the importance of regular security assessments and continuous monitoring of administrative interfaces, as demonstrated by ATT&CK technique T1078 which covers valid accounts and privilege escalation tactics. Organizations should also consider implementing additional controls such as multi-factor authentication for administrative accounts and regular auditing of administrative activities to detect potential exploitation attempts.