CVE-2020-17016 in SharePoint Server
Summary
by MITRE • 11/11/2020
Microsoft SharePoint Spoofing Vulnerability This CVE ID is unique from CVE-2020-17015, CVE-2020-17060.
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Analysis
by VulDB Data Team • 12/05/2020
Microsoft SharePoint contains a spoofing vulnerability that allows attackers to manipulate user interface elements and potentially deceive users into performing unintended actions. This vulnerability specifically affects the way SharePoint handles certain user interface components and can be exploited to present misleading information to end users. The flaw resides in the authentication and authorization mechanisms of SharePoint Server, particularly in how it processes and displays user interface elements during various operations. Attackers can leverage this vulnerability to create deceptive interfaces that appear legitimate to users while actually directing them to malicious endpoints or prompting them to disclose sensitive information. The vulnerability impacts SharePoint Server 2016 and SharePoint Server 2019 installations, where the spoofing occurs during specific interaction patterns with the web interface. This issue falls under the category of CWE-693 Protection Mechanism Failure, as it represents a breakdown in the system's ability to properly validate and protect against unauthorized manipulation of user interface elements. The attack vector typically involves crafting malicious web requests that exploit the vulnerability in the SharePoint rendering engine, allowing for the display of misleading content that can fool even security-aware users. According to ATT&CK framework, this vulnerability maps to T1566 Initial Access through the use of deceptive interfaces and T1071 Application Layer Protocol for the manipulation of web-based communication channels. The operational impact of this vulnerability extends beyond simple deception, as it can enable more sophisticated attacks including credential theft, data exfiltration, and lateral movement within the network. Organizations using SharePoint Server are particularly at risk as this vulnerability can be exploited without requiring elevated privileges, making it an attractive target for adversaries seeking to establish persistent access. The vulnerability is particularly concerning in environments where SharePoint is used for collaboration and document management, as it can be used to manipulate user workflows and potentially compromise sensitive business information. Security researchers have noted that the vulnerability can be combined with other exploitation techniques to create more sophisticated attack chains, particularly when combined with phishing campaigns or other social engineering approaches. The exploitation requires minimal technical skill and can be automated, making it a significant threat to organizations that do not maintain current security patches. Microsoft has addressed this vulnerability through security updates that correct the validation mechanisms in SharePoint's user interface rendering components, requiring administrators to apply the relevant patches to mitigate the risk. Organizations should also implement network monitoring solutions that can detect anomalous behavior patterns associated with the exploitation of this vulnerability and establish user awareness training to help identify potentially deceptive interfaces. The vulnerability highlights the importance of maintaining robust user interface security controls and demonstrates how seemingly minor flaws in authentication and authorization can have significant operational impacts. This issue is classified as a medium to high severity risk and requires immediate attention from security teams to prevent potential exploitation by threat actors. The vulnerability's persistence across multiple SharePoint Server versions indicates that organizations should perform comprehensive assessments of their SharePoint environments to identify all affected systems and ensure proper patch management procedures are in place.