CVE-2011-1891 in SharePoint Foundation
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Microsoft Windows SharePoint Services 3.0 SP2, and SharePoint Foundation 2010 Gold and SP1, allows remote attackers to inject arbitrary web script or HTML via unspecified parameters in a request to a script, aka "Contact Details Reflected XSS Vulnerability."
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Analysis
by VulDB Data Team • 11/18/2021
This cross-site scripting vulnerability exists in Microsoft Windows SharePoint Services 3.0 SP2 and SharePoint Foundation 2010 Gold and SP1 versions, representing a critical security flaw that enables remote attackers to execute malicious scripts within the context of affected systems. The vulnerability specifically manifests when unspecified parameters in HTTP requests are processed by the SharePoint infrastructure without proper input validation or output encoding, creating an attack vector that can be exploited by malicious actors to inject arbitrary web script or HTML content.
The technical nature of this vulnerability aligns with CWE-79, which defines cross-site scripting as a weakness where untrusted data is sent to a web browser without proper validation or encoding. The flaw operates by reflecting user-supplied input directly into web responses without sanitization, allowing attackers to craft malicious payloads that execute in the victim's browser context. When legitimate users interact with the affected SharePoint services, their browsers receive and execute the injected malicious code, potentially leading to session hijacking, credential theft, or other malicious activities.
The operational impact of this vulnerability extends beyond simple script injection, as it can be leveraged to perform sophisticated attacks against authenticated users within the SharePoint environment. Attackers can exploit this weakness to steal session cookies, redirect users to malicious websites, or manipulate the SharePoint interface to gain unauthorized access to sensitive information. The reflected nature of the XSS vulnerability means that the malicious payload is immediately reflected back to the user's browser, making it particularly effective for phishing attacks and social engineering campaigns targeting SharePoint users.
From a threat modeling perspective, this vulnerability maps to several ATT&CK techniques including T1566 for social engineering and T1059 for command and script injection. The attack surface is particularly concerning for organizations using SharePoint as a collaboration platform, as it can be exploited by attackers who gain access to any legitimate user account through initial compromise methods. The vulnerability's presence in widely deployed SharePoint versions means that organizations with legacy systems are particularly at risk, as these platforms often serve as central repositories for corporate information and user credentials.
Mitigation strategies should include implementing comprehensive input validation mechanisms, deploying proper output encoding for all user-supplied data, and configuring web application firewalls to detect and block suspicious script injection attempts. Organizations should also consider implementing content security policies that restrict script execution and regularly update their SharePoint installations to the latest security patches. Additionally, security awareness training for users can help reduce the risk of successful exploitation through phishing campaigns that leverage this vulnerability. The remediation process should prioritize immediate patching of affected systems, followed by comprehensive security audits to identify any potential exploitation attempts that may have occurred prior to patch deployment.