CVE-2007-6397 in Board
Summary
by MITRE
Multiple directory traversal vulnerabilities in index.php in Flat PHP Board 1.2 and earlier allow remote attackers to (1) create arbitrary files via a .. (dot dot) in the username parameter when registering a user account, and (2) read arbitrary PHP files via a .. (dot dot) in (a) the topic parameter in a topic action or (b) the username parameter in a viewprofile action.
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Analysis
by VulDB Data Team • 10/12/2024
The vulnerability described in CVE-2007-6397 represents a critical directory traversal flaw affecting Flat PHP Board version 1.2 and earlier systems. This security weakness manifests in multiple attack vectors that collectively enable remote adversaries to manipulate the application's file system operations. The vulnerability stems from insufficient input validation and sanitization within the application's core processing logic, specifically in the index.php file that handles user registration and profile viewing functionalities. Attackers can exploit these weaknesses to gain unauthorized access to the underlying file system and potentially execute malicious code or exfiltrate sensitive information.
The technical implementation of this vulnerability exploits the fundamental flaw in how the application processes user-supplied input parameters without proper validation or sanitization. During user registration, when the username parameter contains directory traversal sequences such as .. (dot dot), the application fails to properly sanitize this input before using it in file system operations. This allows attackers to create files outside of the intended directory structure, potentially writing malicious code to critical system locations. Similarly, in the topic viewing functionality, when the topic parameter contains traversal sequences, or during profile viewing when the username parameter is manipulated, the application processes these inputs without adequate security checks, enabling attackers to read arbitrary PHP files from the server.
The operational impact of CVE-2007-6397 extends beyond simple file access violations and represents a severe threat to application security and data integrity. An attacker could leverage this vulnerability to read sensitive configuration files, database connection details, or other critical application components that might contain authentication credentials or system information. The ability to create arbitrary files during user registration opens possibilities for code injection attacks where malicious PHP scripts could be placed in web-accessible directories, potentially leading to complete system compromise. This vulnerability directly relates to CWE-22, which describes improper limitation of a pathname to a restricted directory, and aligns with ATT&CK technique T1059 for executing malicious code through web shells or uploaded files.
The attack vectors present in this vulnerability demonstrate how a single input validation flaw can create multiple exploitation pathways within a web application. The combination of file creation and file reading capabilities provides attackers with both persistence mechanisms and information gathering capabilities. The vulnerability affects the application's authentication and authorization mechanisms by allowing manipulation of user registration processes and profile access controls. This weakness can be exploited through standard HTTP requests without requiring special privileges or tools, making it particularly dangerous as it can be leveraged by any remote attacker with basic web browsing capabilities. The vulnerability's impact is amplified by the fact that it affects core application functions and can potentially provide access to sensitive data or system resources that should be protected from unauthorized access. Organizations running affected versions of Flat PHP Board should immediately implement mitigations including input validation, proper parameter sanitization, and access controls to prevent exploitation of these directory traversal vulnerabilities.