CVE-2009-4626 in phpNagios
Summary
by MITRE
Directory traversal vulnerability in menu.php in phpNagios 1.2.0 allows remote attackers to include and execute arbitrary local files via directory traversal sequences in the conf[lang] parameter.
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Analysis
by VulDB Data Team • 04/11/2025
The vulnerability identified as CVE-2009-4626 represents a critical directory traversal flaw within the phpNagios monitoring system version 1.2.0. This issue specifically affects the menu.php script which processes user input through the conf[lang] parameter without proper validation or sanitization. The vulnerability stems from insufficient input filtering that allows malicious actors to manipulate file inclusion mechanisms by crafting specially formatted directory traversal sequences such as ../ or ..\.. The affected system fails to properly validate or sanitize the language parameter, creating an opportunity for attackers to access arbitrary local files on the server filesystem.
This directory traversal vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw enables an attacker to bypass normal access controls and potentially execute arbitrary code on the target system. When an attacker submits malicious input through the conf[lang] parameter, the application processes this input without adequate validation, allowing the inclusion of local files that should otherwise be protected. The vulnerability exists because the application directly incorporates user-supplied data into file paths without proper sanitization or access control mechanisms.
The operational impact of this vulnerability is severe as it provides remote attackers with unauthorized access to sensitive system files and potentially allows for remote code execution. An attacker could leverage this flaw to read system configuration files, access database credentials, retrieve source code, or even gain shell access to the server. The attack surface is particularly concerning because phpNagios is commonly used for network monitoring in enterprise environments, making it a valuable target for attackers seeking persistent access to critical infrastructure. The vulnerability could enable attackers to escalate privileges, establish backdoors, or conduct further reconnaissance within the network.
Mitigation strategies for CVE-2009-4626 should include immediate patching of the phpNagios application to version 1.2.1 or later, which contains the necessary input validation fixes. Organizations should implement proper parameter validation and sanitization for all user inputs, particularly those used in file inclusion operations. Input filtering should be implemented at multiple layers including application-level validation, web application firewalls, and network-level controls. Security configurations should enforce strict access controls and limit the application's ability to traverse filesystem paths. Additionally, the principle of least privilege should be applied to restrict file access permissions and prevent unauthorized file access. Network segmentation and monitoring should be employed to detect and prevent exploitation attempts. The vulnerability also highlights the importance of regular security assessments and vulnerability management processes to identify and remediate similar issues in legacy systems. This case demonstrates the critical need for secure coding practices and input validation in web applications to prevent directory traversal attacks that can lead to complete system compromise.