CVE-2006-4639 in C-News
Summary
by MITRE
Multiple PHP remote file inclusion vulnerabilities in C-News.fr C-News 1.0.1 and earlier, when register_globals is enabled, allow remote attackers to execute arbitrary PHP code via a URL in the path parameter in (1) formulaire_commentaires.php, (2) affichage/liste_news.php, (3) affichage/news_complete.php, or (4) affichage/pagination.php. NOTE: the provenance of some of this information is unknown; some details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/03/2018
The CVE-2006-4639 vulnerability represents a critical remote code execution flaw in C-News.fr C-News version 1.0.1 and earlier, specifically targeting PHP applications where register_globals is enabled. This vulnerability falls under the CWE-94 category of Code Injection, more specifically manifesting as a PHP Remote File Inclusion (RFI) vulnerability that exploits insecure parameter handling within the application's core components. The flaw exists in multiple files including formulaire_commentaires.php, affichage/liste_news.php, affichage/news_complete.php, and affichage/pagination.php, making it a widespread issue across the application's user interaction modules.
The technical exploitation of this vulnerability occurs through the manipulation of the path parameter in the affected PHP files, leveraging the dangerous combination of register_globals being enabled and improper input validation. When register_globals is active, PHP automatically creates global variables from HTTP request data, including GET, POST, and COOKIE parameters. Attackers can craft malicious URLs that include PHP code within the path parameter, which then gets included and executed by the vulnerable application. This mechanism allows adversaries to inject arbitrary PHP code into the web server's execution environment, effectively bypassing normal security boundaries and gaining unauthorized access to the server's functionality.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with complete control over the affected web server. Successful exploitation enables remote code execution, allowing attackers to perform actions such as data theft, system compromise, server takeover, and deployment of additional malicious payloads. The vulnerability's presence in multiple files means that attackers can target different entry points within the application, increasing the attack surface and making detection and prevention more challenging. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1190 for exploiting vulnerabilities in web applications, and represents a classic example of how insecure input handling can lead to complete system compromise.
Mitigation strategies for CVE-2006-4639 must address both the immediate vulnerability and underlying architectural issues. The primary defense involves disabling register_globals in the PHP configuration, which immediately eliminates the automatic creation of global variables from request data. Additionally, implementing proper input validation and sanitization across all user-supplied parameters is essential, ensuring that any path parameter values are strictly validated against a whitelist of acceptable inputs. The application should employ secure coding practices such as using include() with absolute paths and avoiding dynamic path construction from user input. Organizations should also consider implementing web application firewalls to detect and block malicious URL patterns, while maintaining regular security audits to identify similar vulnerabilities in other applications. The vulnerability demonstrates the critical importance of following secure coding guidelines and the dangers of legacy PHP configurations that enable dangerous features like register_globals.