CVE-2009-3757 in XenCenterWeb
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in sample code in the XenServer Resource Kit in Citrix XenCenterWeb allow remote attackers to inject arbitrary web script or HTML via the (1) username parameter to config/edituser.php; (2) location, (3) sessionid, and (4) vmname parameters to console.php; (5) vmrefid and (6) vmname parameters to forcerestart.php; and (7) vmname and (8) vmrefid parameters to forcesd.php. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 12/03/2024
The vulnerability described in CVE-2009-3757 represents a critical cross-site scripting weakness within the XenServer Resource Kit sample code distributed by Citrix through XenCenterWeb. This issue affects multiple PHP scripts including edituser.php, console.php, forcerestart.php, and forcesd.php, exposing the XenServer management interface to persistent security threats. The vulnerability stems from inadequate input validation and sanitization mechanisms within the sample code that fails to properly escape or filter user-supplied parameters before incorporating them into web responses. These flaws are particularly concerning as they exist within sample code that administrators might inadvertently deploy or modify, creating potential attack vectors in production environments.
The technical exploitation of these XSS vulnerabilities occurs through manipulation of specific HTTP parameters that are processed by the affected PHP scripts. Attackers can inject malicious JavaScript code through the username parameter in edituser.php or through location, sessionid, and vmname parameters in console.php. The forcerestart.php script is vulnerable through vmrefid and vmname parameters, while forcesd.php accepts malicious input through vmname and vmrefid parameters. These vulnerabilities fall under CWE-79 which specifically addresses cross-site scripting flaws where untrusted data is improperly incorporated into web pages without proper validation or encoding. The attack surface is broad as these parameters are likely to be processed during normal administrative operations, making the exploitation particularly dangerous.
The operational impact of these vulnerabilities extends beyond simple script injection, as they can enable attackers to perform session hijacking, steal administrative credentials, or manipulate the XenServer management interface. Successful exploitation could allow an attacker to gain unauthorized access to virtual machine management functions, potentially leading to complete compromise of the virtualized infrastructure. The presence of these vulnerabilities in sample code is particularly problematic because administrators might assume that such code is secure or might not properly validate inputs, creating a false sense of security. This issue demonstrates how insecure coding practices in sample applications can propagate to production environments, as organizations may copy or modify these examples without proper security review. The attack vector requires remote access and user interaction, making it particularly dangerous in environments where administrators frequently interact with the XenCenterWeb interface.
Mitigation strategies for CVE-2009-3757 should focus on immediate remediation of the affected sample code and comprehensive input validation implementation. Organizations should ensure that all user-supplied parameters are properly sanitized and encoded before being rendered in web responses, implementing proper output encoding techniques such as HTML entity encoding for all dynamic content. The recommended approach aligns with ATT&CK technique T1203 which involves exploiting input validation weaknesses in web applications. Security patches should be applied to update the XenServer Resource Kit to versions that address these XSS vulnerabilities, and administrators should conduct thorough code reviews of any custom modifications to the sample code. Additionally, implementing Content Security Policy (CSP) headers can provide an additional layer of protection against XSS attacks by restricting script execution within the browser. Regular security assessments of administrative interfaces and input validation practices should be conducted to prevent similar vulnerabilities from emerging in future deployments.