CVE-2011-1263 in Windows
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the logon page in Remote Desktop Web Access (RD Web Access) in Microsoft Windows Server 2008 R2 and R2 SP1 allows remote attackers to inject arbitrary web script or HTML via the URI, aka "Remote Desktop Web Access Vulnerability."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/15/2025
The CVE-2011-1263 vulnerability represents a critical cross-site scripting flaw in Microsoft Windows Server 2008 R2 and R2 SP1 Remote Desktop Web Access functionality. This vulnerability specifically targets the logon page of RD Web Access, which serves as the web-based interface for remote desktop connections. The flaw enables remote attackers to execute malicious scripts by manipulating the URI parameters during the authentication process, creating a significant security risk for organizations relying on this web access mechanism.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the RD Web Access logon page. When users navigate to the web access interface, the system fails to properly sanitize user-supplied URI parameters before rendering them in the web response. This improper handling allows attackers to inject malicious JavaScript code or HTML content directly into the authentication page. The vulnerability specifically manifests when the system processes URI parameters without adequate sanitization, creating an XSS vector that can be exploited by remote threat actors.
The operational impact of CVE-2011-1263 extends beyond simple script injection, as it can be leveraged for more sophisticated attacks within the target environment. An attacker could potentially redirect authenticated users to malicious sites, steal session cookies, or execute arbitrary code within the context of the victim's browser session. This vulnerability particularly affects organizations that rely on RD Web Access for remote desktop connectivity, as it undermines the integrity of the authentication process and could lead to unauthorized access to corporate networks. The vulnerability is classified under CWE-79 as Improper Neutralization of Input During Web Page Generation, which directly relates to the failure to properly encode output in web applications.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1566.001 for Initial Access through Spearphishing Attachments and T1071.001 for Application Layer Protocol for Command and Control. The attack surface is particularly concerning for enterprise environments where RD Web Access is exposed to untrusted networks, as it provides a potential entry point for attackers to establish persistent access or escalate privileges within the network infrastructure.
Organizations should implement multiple layers of mitigation strategies to address this vulnerability effectively. The primary recommendation involves applying the relevant Microsoft security updates that patch the XSS vulnerability in RD Web Access. Additionally, network segmentation should be implemented to limit direct exposure of RD Web Access to external networks, while web application firewalls can provide additional filtering for suspicious URI parameters. Input validation controls should be strengthened at the application level to ensure all user-supplied data is properly sanitized before processing, and output encoding should be enforced to prevent script execution in web responses. Regular security assessments and penetration testing should verify that the implemented controls effectively mitigate the risk associated with this vulnerability.