CVE-2009-1801 in FreePBX
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in FreePBX 2.5.1, and other 2.4.x, 2.5.x, and pre-release 2.6.x versions, allow remote attackers to inject arbitrary web script or HTML via the (1) display parameter to reports.php, the (2) order and (3) extdisplay parameters to config.php, and the (4) sort parameter to recordings/index.php. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 11/10/2018
The vulnerability described in CVE-2009-1801 represents a critical cross-site scripting flaw affecting FreePBX versions 2.5.1 and earlier releases within the 2.4.x, 2.5.x, and pre-release 2.6.x series. This vulnerability stems from inadequate input validation and output encoding mechanisms within the web application's user interface components, specifically targeting four distinct parameters across different PHP scripts that handle user interactions and data display within the telephony management system.
The technical exploitation of this vulnerability occurs through the manipulation of four specific parameters that are processed by different application modules. The display parameter in reports.php accepts unfiltered user input that gets directly embedded into HTML output without proper sanitization, allowing attackers to inject malicious scripts. Similarly, the order and extdisplay parameters in config.php fail to validate or escape user-supplied data before rendering it in the web interface. The sort parameter in recordings/index.php presents another vector where user input is processed without adequate security controls, creating opportunities for persistent script injection attacks. These flaws collectively represent a classic case of insufficient input validation and output encoding, which falls under CWE-79 - Improper Neutralization of Input During Web Page Generation.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform various malicious activities including session hijacking, credential theft, and unauthorized access to the telephony system. An attacker could craft malicious URLs containing script payloads that, when visited by an authenticated user with appropriate privileges, would execute in the victim's browser context. This could lead to complete compromise of the FreePBX management interface, potentially allowing unauthorized modifications to phone system configurations, access to call recordings, and control over voicemail systems. The vulnerability is particularly concerning because FreePBX systems are often deployed in enterprise environments where they serve as critical communication infrastructure, making successful exploitation a significant security incident that could disrupt business operations and compromise sensitive communications data.
Mitigation strategies for CVE-2009-1801 should prioritize immediate patching of affected FreePBX installations to version 2.5.2 or later, which includes proper input validation and output encoding fixes. Organizations should implement comprehensive input sanitization across all web application parameters, particularly those used for dynamic content generation and user interface configuration. The implementation of Content Security Policy headers can provide additional defense-in-depth measures to prevent script execution even if input validation fails. Regular security assessments of web applications should include thorough testing of input handling mechanisms, with particular attention to parameters used in report generation, configuration management, and file listing operations. This vulnerability demonstrates the importance of following secure coding practices and adheres to ATT&CK technique T1213 - Data from Information Repositories, where attackers can leverage web application vulnerabilities to gain unauthorized access to system information and control mechanisms. Organizations should also consider implementing web application firewalls to detect and block malicious input patterns associated with XSS attacks, and establish regular security monitoring procedures to identify potential exploitation attempts against known vulnerabilities.