CVE-2009-2277 in ESX Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in WebAccess in VMware VirtualCenter 2.0.2 and 2.5 and VMware ESX 3.0.3 and 3.5 allows remote attackers to inject arbitrary web script or HTML via vectors related to "context data."
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Analysis
by VulDB Data Team • 05/04/2026
The vulnerability described in CVE-2009-2277 represents a critical cross-site scripting weakness within VMware VirtualCenter's WebAccess component, affecting versions 2.0.2 and 2.5 as well as VMware ESX versions 3.0.3 and 3.5. This flaw resides in the handling of context data within the web interface, creating an avenue for remote attackers to execute malicious code through web-based payloads. The vulnerability operates at the application layer and specifically targets the user authentication and session management mechanisms that are fundamental to virtualization environments.
The technical implementation of this XSS vulnerability stems from insufficient input validation and output encoding within the WebAccess interface of VMware VirtualCenter. When the system processes context data from user inputs or HTTP request parameters, it fails to properly sanitize or escape special characters that could be interpreted as HTML or JavaScript code. This weakness allows attackers to inject malicious scripts that execute in the context of other users' browsers, potentially compromising user sessions and enabling unauthorized access to sensitive virtualization management functions. The vulnerability aligns with CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, steal administrative credentials, and gain unauthorized access to virtual machine configurations. Attackers can craft malicious URLs or HTML content that, when viewed by authenticated users, executes scripts that capture session cookies or redirect users to malicious sites. In virtualized environments where VMware VirtualCenter serves as the primary management interface, this vulnerability can be leveraged to compromise entire virtual infrastructures, as successful exploitation could lead to unauthorized access to virtual machines, hypervisor configurations, and network settings. The attack vector demonstrates characteristics consistent with ATT&CK technique T1059.007 for Command and Scripting Interpreter, specifically targeting web-based scripting environments.
Mitigation strategies for CVE-2009-2277 should include immediate patching of affected VMware VirtualCenter and ESX versions, implementing proper input validation and output encoding mechanisms, and deploying web application firewalls to filter malicious payloads. Organizations should also consider network segmentation to limit access to management interfaces and implement strict access controls to minimize the potential impact of successful exploitation. The vulnerability highlights the importance of secure coding practices in enterprise virtualization platforms and demonstrates how seemingly minor input validation flaws can create significant security risks in complex IT infrastructures. Regular security assessments and vulnerability scanning should be implemented to identify similar weaknesses in other components of virtualization management systems.