CVE-2017-11936 in SharePoint Enterprise Server
Summary
by MITRE
Microsoft SharePoint Enterprise Server 2016 allows an elevation of privilege vulnerability due to the way web requests are handled, aka "Microsoft SharePoint Elevation of Privilege Vulnerability".
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Analysis
by VulDB Data Team • 01/27/2021
The vulnerability identified as CVE-2017-11936 represents a critical elevation of privilege flaw within Microsoft SharePoint Enterprise Server 2016 that stems from improper handling of web requests within the application's security framework. This vulnerability falls under the category of privilege escalation attacks where an authenticated user can potentially gain elevated access rights beyond their normal permissions. The flaw exists in the server's processing of web requests and specifically affects how the system validates and authorizes user actions within the SharePoint environment. Security researchers have classified this issue as a significant risk to organizations relying on SharePoint 2016 for their collaboration and document management needs, as it could allow attackers to bypass normal access controls and perform unauthorized operations.
The technical root cause of this vulnerability lies in the SharePoint server's insufficient validation of web request parameters and the way it processes user authentication tokens during web-based operations. When a user submits a web request to the SharePoint server, the system fails to properly verify the legitimacy of certain request components that could be manipulated by an attacker. This weakness creates an opportunity for malicious actors to exploit the system's trust model and escalate their privileges without proper authentication. The vulnerability is particularly concerning because it requires minimal privileges to exploit, meaning that even users with standard access rights could potentially leverage this flaw to gain administrative capabilities within the SharePoint environment. This type of flaw typically maps to CWE-284, which describes improper access control issues in software systems.
The operational impact of CVE-2017-11936 extends beyond simple privilege escalation, as it creates potential for broader security breaches within SharePoint environments. Attackers who successfully exploit this vulnerability could access sensitive corporate data, modify or delete documents, manipulate user permissions, and potentially establish persistent access to the system. The implications are particularly severe in enterprise environments where SharePoint servers often host critical business information and serve as central collaboration platforms. Organizations may face significant data exposure risks, compliance violations, and potential regulatory penalties if this vulnerability is exploited successfully. The vulnerability also enables attackers to potentially use the elevated privileges to pivot into other systems within the network, as SharePoint servers often have access to various internal resources and databases. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques and could be leveraged for lateral movement within compromised environments.
Mitigation strategies for CVE-2017-11936 primarily focus on applying Microsoft's official security patches and updates as soon as they become available. Organizations should prioritize immediate deployment of the relevant security update from Microsoft's monthly security bulletin releases, which specifically address this vulnerability. Additionally, implementing network segmentation and access controls can help limit the potential damage if exploitation occurs, while monitoring web request patterns can aid in detecting suspicious activities that might indicate exploitation attempts. Security teams should also consider implementing additional authentication layers and regularly reviewing user permissions to minimize the impact of any potential privilege escalation. Organizations should conduct thorough security assessments of their SharePoint environments to identify any additional vulnerabilities that may compound the risk from this specific flaw. Regular security awareness training for administrators and users can also help prevent social engineering attacks that might be used in conjunction with this technical vulnerability to achieve successful exploitation.