CVE-2007-0761 in ezBoard converter
Summary
by MITRE
PHP remote file inclusion vulnerability in config.php in phpBB ezBoard converter (ezconvert) 0.2 allows remote attackers to execute arbitrary PHP code via a URL in the ezconvert_dir parameter.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/21/2024
The vulnerability identified as CVE-2007-0761 represents a critical remote file inclusion flaw within the phpBB ezBoard converter version 0.2, specifically affecting the config.php file. This vulnerability falls under the category of insecure direct object references and improper input validation, creating a pathway for malicious actors to execute arbitrary code on vulnerable systems. The flaw manifests when the ezconvert_dir parameter is manipulated through URL input, allowing attackers to inject malicious file paths that the application subsequently includes and executes without proper validation or sanitization.
The technical implementation of this vulnerability stems from the converter's failure to properly validate user-supplied input before using it in file inclusion operations. When the ezconvert_dir parameter is passed to the config.php script, the application directly incorporates this parameter into file inclusion directives without adequate sanitization. This creates an environment where an attacker can supply a malicious URL, potentially pointing to a remote server hosting malicious PHP code, thereby enabling remote code execution on the target system. The vulnerability is classified as a remote code execution flaw, which aligns with common weakness enumerations such as CWE-94 and CWE-434, both of which address improper input validation and insecure file inclusion practices.
The operational impact of this vulnerability is severe and far-reaching, as it allows attackers to gain complete control over affected systems. An attacker exploiting this vulnerability can execute arbitrary PHP code, potentially leading to data breaches, system compromise, and unauthorized access to sensitive information. The remote nature of the attack means that exploitation can occur from anywhere on the internet, making it particularly dangerous for web applications that are publicly accessible. This vulnerability directly maps to tactics outlined in the attack mitigation framework, specifically targeting the execution and persistence phases where adversaries seek to establish control over compromised systems. The converter's reliance on user input for file paths without proper validation creates a persistent threat vector that can be leveraged for various malicious activities including data exfiltration, privilege escalation, and further network infiltration.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements. The primary fix involves implementing strict input validation and sanitization for all user-supplied parameters, particularly those used in file inclusion operations. Organizations should enforce the principle of least privilege by restricting file inclusion to predefined, trusted directories only, thereby eliminating the possibility of remote file inclusion attacks. Additionally, the implementation of secure coding practices including the use of allowlists for valid input values, proper parameter validation, and the elimination of dynamic file inclusion based on user input are essential. The vulnerability also highlights the importance of regular security assessments and code reviews to identify similar patterns of insecure coding practices that could lead to analogous weaknesses. System administrators should ensure that vulnerable applications are updated to patched versions or replaced with secure alternatives, while implementing network monitoring and intrusion detection systems to identify potential exploitation attempts. This vulnerability serves as a critical reminder of the importance of input validation and the potential catastrophic consequences of failing to properly sanitize user input in web applications.