CVE-2006-4034 in ModernBill
Summary
by MITRE
PHP remote file inclusion vulnerability in include/html/config.php in ModernGigabyte ModernBill 1.6 allows remote attackers to execute arbitrary PHP code via a URL in the DIR parameter.
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Analysis
by VulDB Data Team • 08/01/2018
The vulnerability identified as CVE-2006-4034 represents a critical remote file inclusion flaw in ModernGigabyte ModernBill version 1.6 that fundamentally compromises the security posture of affected systems. This vulnerability exists within the include/html/config.php file where the application fails to properly validate or sanitize user input passed through the DIR parameter. The flaw enables remote attackers to inject malicious URLs that are subsequently included and executed as PHP code, creating a pathway for arbitrary code execution on the target server. Such vulnerabilities fall under the category of CWE-98 - Improper Control of Generation of Code, which specifically addresses issues where applications fail to properly control the generation or execution of code based on user-supplied input. The attack vector leverages the inherent trust placed in local file inclusion mechanisms within PHP applications, exploiting the lack of proper input sanitization and validation.
The technical exploitation of this vulnerability requires an attacker to craft a malicious URL that gets passed through the DIR parameter, which is then processed by the vulnerable application. When ModernBill 1.6 processes this parameter, it directly incorporates the user-supplied URL into the include statement without proper validation, allowing the attacker to reference external malicious PHP scripts. This creates a scenario where the web server executes code from remote locations, effectively granting attackers complete control over the affected system. The vulnerability is particularly dangerous because it operates at the application layer, bypassing many traditional network-based security controls and directly compromising the server's execution environment. This type of vulnerability is classified under the ATT&CK technique T1190 - Exploit Public-Facing Application, which specifically addresses the exploitation of vulnerabilities in publicly accessible web applications.
The operational impact of CVE-2006-4034 extends far beyond simple code execution, as it provides attackers with complete system compromise capabilities. Once exploited, attackers can establish persistent access, install backdoors, exfiltrate sensitive data, and use the compromised server as a launch point for further attacks within the network infrastructure. The vulnerability affects the confidentiality, integrity, and availability of the affected systems, as it allows unauthorized modifications to the application code and potential denial of service through resource exhaustion. Organizations running ModernBill 1.6 are at significant risk of data breaches, system infiltration, and regulatory compliance violations. The vulnerability's impact is amplified by the fact that it requires no special privileges or access to the system itself, making it particularly attractive to attackers who may be targeting multiple systems simultaneously. Security professionals should consider this vulnerability as a critical threat that requires immediate attention and remediation to prevent potential widespread compromise across affected deployments.
Mitigation strategies for CVE-2006-4034 must address both the immediate vulnerability and broader security posture improvements. The most effective immediate solution involves patching the application to version 1.6.1 or later, which contains the necessary fixes to prevent remote file inclusion attacks. Organizations should also implement input validation and sanitization measures that prevent user-supplied parameters from being used in include statements without proper verification. Additionally, the principle of least privilege should be enforced by configuring web servers to restrict file inclusion operations and disable remote file access capabilities. Security measures should include network segmentation, intrusion detection systems, and regular security assessments to identify similar vulnerabilities in other applications. Organizations must also consider implementing web application firewalls to detect and block malicious requests targeting known vulnerability patterns. The remediation process should include thorough testing to ensure that patches do not introduce regressions while maintaining the application's functionality and performance. Regular security updates and vulnerability assessments remain essential practices to prevent similar issues from emerging in the future, particularly given the historical context of this vulnerability and the prevalence of similar flaws in legacy web applications.