CVE-2006-4559 in Yet Another Community System Cms
Summary
by MITRE
Multiple PHP remote file inclusion vulnerabilities in Yet Another Community System (YACS) CMS 6.6.1 allow remote attackers to execute arbitrary PHP code via a URL in the context[path_to_root] parameter in (1) articles/populate.php, (2) categories/category.php, (3) categories/populate.php, (4) comments/populate.php, (5) files/file.php, (6) sections/section.php, (7) sections/populate.php, (8) tables/populate.php, (9) users/user.php, and (10) users/populate.php. The articles/article.php vector is covered by CVE-2006-4532.
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Analysis
by VulDB Data Team • 08/07/2017
The vulnerability described in CVE-2006-4559 represents a critical remote file inclusion flaw within the Yet Another Community System CMS version 6.6.1, exposing multiple attack vectors across various components of the application. This vulnerability falls under the category of insecure direct object references and improper input validation, allowing malicious actors to inject arbitrary PHP code through carefully crafted URLs. The affected files demonstrate a widespread pattern of improper parameter handling where user-supplied input is directly incorporated into file inclusion operations without adequate sanitization or validation. The specific parameter context[path_to_root] serves as the primary attack vector, enabling attackers to manipulate the application's file inclusion mechanisms and execute malicious code remotely.
The technical exploitation of this vulnerability leverages the fundamental weakness in how the CMS handles file paths and includes, creating a pathway for remote code execution that bypasses normal application security controls. When an attacker supplies a malicious URL through the path_to_root parameter, the application processes this input directly within include or require statements, potentially loading and executing remote PHP code from external servers. This flaw operates at the application level and demonstrates poor input validation practices, where the system fails to properly sanitize or validate user-provided paths before using them in file operations. The vulnerability affects multiple modules including articles, categories, comments, files, sections, tables, and users, indicating a systemic architectural weakness rather than isolated component failure.
The operational impact of this vulnerability is severe and far-reaching, as it allows attackers to gain complete control over the affected web server hosting the YACS CMS. Successful exploitation can lead to data breaches, system compromise, and potential lateral movement within the network infrastructure. Attackers can upload backdoors, exfiltrate sensitive data, modify content, or establish persistent access to the compromised system. The vulnerability affects the core functionality of the content management system and can result in complete loss of service availability. Organizations running this version of YACS are particularly at risk as the vulnerability exists across multiple modules, providing attackers with numerous entry points and increasing the likelihood of successful exploitation. This flaw directly violates security principles outlined in the OWASP Top Ten and represents a critical weakness in application input handling and file inclusion security.
Mitigation strategies for this vulnerability require immediate action including applying the vendor-provided security patches or upgrading to a newer version of the YACS CMS that addresses these issues. Organizations should implement proper input validation and sanitization measures to prevent user-supplied data from being processed in file inclusion operations. The implementation of a web application firewall can provide additional protection by filtering malicious requests before they reach the vulnerable application components. Regular security audits and code reviews should focus on identifying similar patterns of insecure file handling and input validation. The vulnerability aligns with CWE-98 and CWE-22 categories, representing improper input validation and path traversal issues respectively, and follows attack patterns documented in the MITRE ATT&CK framework under initial access and execution phases. Organizations should also consider implementing network segmentation and monitoring to detect and prevent exploitation attempts, while maintaining up-to-date security information exchange feeds to stay informed about similar vulnerabilities in their software ecosystem.