CVE-2009-4038 in Axon Virtual PBX
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in NCH Software Axon Virtual PBX 2.10 and 2.11 allow remote attackers to inject arbitrary web script or HTML via the (1) onok or (2) oncancel parameter to the logon program. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 08/28/2021
The vulnerability identified as CVE-2009-4038 represents a critical cross-site scripting flaw affecting NCH Software Axon Virtual PBX versions 2.10 and 2.11. This security weakness resides in the authentication mechanism of the system's logon program, specifically in how it processes user input parameters. The vulnerability stems from inadequate input validation and sanitization practices within the web application framework, creating an attack vector that allows malicious actors to execute arbitrary JavaScript code within the context of authenticated user sessions. The affected parameters onok and oncancel serve as entry points for injection attacks, demonstrating poor security design principles that violate fundamental web application security practices.
The technical implementation of this vulnerability involves the improper handling of user-supplied data in the web interface components of the Axon Virtual PBX system. When users interact with the login page, the application fails to properly sanitize or escape input values before incorporating them into dynamic web content. This allows attackers to craft malicious payloads that, when processed by the browser, execute unintended scripts with the privileges of authenticated users. The vulnerability operates at the application layer and specifically targets the client-side execution environment, making it particularly dangerous as it can bypass traditional network-based security controls. According to CWE classification, this represents a CWE-79: Cross-site Scripting vulnerability, which is a well-documented weakness in web application security that enables attackers to inject client-side scripts into web pages viewed by other users.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with the capability to perform session hijacking, credential theft, and data manipulation within the context of the affected system. An attacker could potentially redirect users to malicious websites, steal session cookies, or even modify the functionality of the virtual PBX interface to gain unauthorized access to voice communication systems. The remote exploitability of this vulnerability means that attackers do not require physical access to the network or system, making it particularly concerning for enterprise environments where such systems are commonly deployed. This vulnerability aligns with ATT&CK technique T1566.001 for initial access through malicious links, and T1071.001 for application layer protocol usage, demonstrating how the flaw can be leveraged in broader attack chains. The potential for privilege escalation exists if the authenticated sessions have elevated permissions within the PBX system.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The most effective immediate solution involves sanitizing all user-supplied input parameters, particularly those used in dynamic content generation, and ensuring proper HTML entity encoding before any user data is rendered in web pages. System administrators should also implement web application firewalls to detect and block suspicious input patterns, while also considering the deployment of content security policies to limit script execution within the application context. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other components of the system, as this flaw demonstrates a pattern of inadequate input handling that may exist elsewhere in the application. The vulnerability highlights the importance of following secure coding practices and implementing defense-in-depth strategies that protect against common web application attacks. Organizations should also consider updating to patched versions of the software, if available, and implementing monitoring solutions to detect potential exploitation attempts.