CVE-2023-33159 in SharePoint Server
Summary
by MITRE • 07/11/2023
Microsoft SharePoint Server Spoofing Vulnerability
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/11/2026
Microsoft SharePoint Server contains a spoofing vulnerability that allows attackers to manipulate user interfaces and potentially deceive users into performing unintended actions. This vulnerability stems from insufficient validation of user-supplied input within the SharePoint Server environment, particularly affecting how the system handles URL parameters and user interface elements. The flaw enables malicious actors to craft deceptive web pages or manipulate existing SharePoint interfaces to appear legitimate while executing unauthorized operations. According to CWE-601, this represents a URL redirection vulnerability where the application fails to properly validate or sanitize input that controls navigation behavior, creating opportunities for attackers to redirect users to malicious sites or manipulate interface elements. The vulnerability is particularly concerning in enterprise environments where SharePoint servers host sensitive business data and collaborative workspaces.
The technical implementation of this spoofing vulnerability occurs when SharePoint Server processes user-provided URLs or parameters without adequate sanitization or validation. Attackers can exploit this weakness by crafting specially formatted links or manipulating interface elements to display misleading information or redirect users to phishing sites. The vulnerability affects various SharePoint Server components including web parts, navigation controls, and user interface rendering mechanisms that rely on external input for display purposes. When users interact with these manipulated elements, the system may present deceptive content that appears to originate from legitimate SharePoint sources. This type of attack leverages the trust users place in familiar SharePoint interfaces, making it particularly effective for social engineering campaigns. The vulnerability's impact is amplified in environments where SharePoint servers are integrated with other Microsoft services, potentially allowing attackers to escalate privileges or access additional resources through the spoofed interface elements.
The operational impact of this vulnerability extends beyond simple deception to potentially enable more serious security incidents including credential theft, data exfiltration, and privilege escalation. Users who fall victim to spoofing attacks may unknowingly provide authentication credentials to malicious sites or execute unauthorized commands through manipulated SharePoint interfaces. In enterprise settings, this vulnerability can compromise sensitive business information stored within SharePoint libraries, document management systems, and collaborative workspaces. The attack surface is particularly broad given that SharePoint Server is commonly used for internal collaboration, external client portals, and document sharing across organizations. Organizations may experience reputational damage if users are successfully deceived into performing malicious actions through spoofed interfaces, potentially leading to compliance violations and regulatory penalties. The vulnerability also creates opportunities for attackers to establish persistence within networks by leveraging the trust relationships inherent in legitimate SharePoint environments.
Mitigation strategies for this SharePoint Server spoofing vulnerability should address both immediate defensive measures and long-term architectural improvements. Organizations should implement strict input validation and sanitization controls across all SharePoint Server components that process user-supplied data, particularly focusing on URL parameters and interface element configurations. The implementation of content security policies and strict origin validation can help prevent unauthorized redirections and ensure that interface elements maintain their intended behavior. Regular security updates and patches from Microsoft should be applied promptly to address known vulnerabilities, with particular attention to SharePoint Server security releases. Network monitoring solutions should be configured to detect unusual navigation patterns or attempts to redirect users to external domains that may indicate spoofing attempts. Organizations should also conduct regular security awareness training to help users recognize potential spoofing indicators and understand the risks associated with clicking suspicious links or interacting with unfamiliar interface elements within SharePoint environments. According to ATT&CK framework, this vulnerability maps to T1566 for social engineering and T1071 for application layer protocol usage, highlighting the need for comprehensive defensive strategies that address both technical controls and user education.