CVE-2015-1633 in SharePoint
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Microsoft SharePoint Foundation 2010 SP2, SharePoint Server 2010 SP2, SharePoint Foundation 2013 Gold and SP1, and SharePoint Server 2013 Gold and SP1 allows remote authenticated users to inject arbitrary web script or HTML via a crafted request, aka "Microsoft SharePoint XSS Vulnerability."
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Analysis
by VulDB Data Team • 04/15/2022
The CVE-2015-1633 vulnerability represents a critical cross-site scripting flaw affecting multiple versions of Microsoft SharePoint platforms including SharePoint Foundation 2010 SP2, SharePoint Server 2010 SP2, SharePoint Foundation 2013 Gold and SP1, and SharePoint Server 2013 Gold and SP1. This vulnerability operates under the Common Weakness Enumeration CWE-79 classification, which specifically addresses cross-site scripting weaknesses in web applications. The flaw enables remote authenticated attackers to inject malicious web scripts or HTML content through carefully crafted requests, exploiting the platform's insufficient input validation and output encoding mechanisms. The vulnerability's impact is particularly concerning given SharePoint's widespread deployment across enterprise environments where users frequently interact with web-based collaboration platforms.
The technical exploitation of this XSS vulnerability occurs when authenticated users submit malicious payloads through SharePoint's web interface or API endpoints. The vulnerability stems from inadequate sanitization of user-supplied input data within SharePoint's rendering and processing pipelines, allowing attackers to inject script code that executes in the context of other users' browsers. This creates a persistent threat vector where malicious scripts can access session cookies, perform actions on behalf of users, steal sensitive information, or redirect users to malicious sites. The attack requires authentication but does not necessitate elevated privileges, making it particularly dangerous in environments where SharePoint serves as a collaboration platform with broad user access.
The operational impact of CVE-2015-1633 extends beyond simple script injection, as it can enable attackers to establish persistent footholds within SharePoint environments and potentially escalate privileges through session hijacking or credential theft. Attackers can leverage this vulnerability to perform various malicious activities including data exfiltration, privilege escalation, or creating backdoor access points within the SharePoint infrastructure. The vulnerability's presence in both Foundation and Server editions means that organizations deploying either platform are at risk, with the impact being particularly severe in environments where SharePoint serves as a central collaboration and document management platform. This vulnerability aligns with the MITRE ATT&CK framework's technique T1059 for Command and Scripting Interpreter and T1566 for Phishing, as attackers can use the XSS to deliver malicious payloads and establish initial access vectors.
Organizations should implement multiple layers of mitigation for this vulnerability including immediate patching of affected SharePoint installations, deployment of web application firewalls to detect and block malicious script injection attempts, and enhanced input validation controls. Microsoft released security updates specifically addressing this vulnerability in their monthly security bulletins, and administrators should prioritize applying these patches to all affected systems. Additional protective measures include implementing strict content security policies, enabling proper output encoding for all user-generated content, and conducting regular security assessments of SharePoint environments to identify potential injection points. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against persistent threats in collaborative platforms.