CVE-2002-2167 in 123tkShop
Summary
by MITRE
Directory traversal vulnerability in function_foot_1.inc.php for Thorsten Korner 123tkShop before 0.3.1 allows remote attackers to read arbitrary files via .. (dot dot) sequences terminated by a null character in the $designNo variable, which is part of an "include" function call.
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Analysis
by VulDB Data Team • 07/11/2024
This vulnerability represents a classic directory traversal flaw that affects the 123tkShop e-commerce platform version 0.3.0 and earlier. The issue resides in the function_foot_1.inc.php file where the $designNo variable is processed without proper input validation before being used in an include function call. This allows malicious actors to manipulate file paths by injecting .. (dot dot) sequences terminated by null characters, effectively bypassing directory restrictions and gaining unauthorized access to arbitrary files on the server. The vulnerability specifically exploits the lack of sanitization in the variable processing logic that handles design parameters for the application's template system.
The technical exploitation occurs when an attacker crafts a malicious payload containing directory traversal sequences such as ../../../etc/passwd or similar file paths that terminate with null characters. These sequences are processed within the include function call without proper validation, allowing the application to resolve paths that extend beyond the intended directory boundaries. The null character termination is particularly significant as it can bypass certain input validation mechanisms that might otherwise detect or filter out standard traversal sequences. This type of vulnerability falls under CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a fundamental weakness in file path handling that has been consistently documented across numerous applications and platforms.
The operational impact of this vulnerability is substantial as it provides remote attackers with the ability to read arbitrary files from the server filesystem, potentially exposing sensitive information such as configuration files, database credentials, application source code, and system files. An attacker could leverage this vulnerability to gain insights into the application's architecture, discover additional vulnerabilities, or extract credentials that could lead to further compromise of the system. The vulnerability affects the core functionality of the 123tkShop platform, potentially compromising the integrity and confidentiality of all data managed by the application. This type of attack aligns with ATT&CK technique T1083 - File and Directory Discovery, where adversaries seek to understand the target environment and identify valuable files for exploitation.
Mitigation strategies should focus on implementing proper input validation and sanitization for all user-supplied data that influences file operations. The recommended approach includes validating the $designNo variable against a whitelist of allowed values, implementing strict path validation that prevents directory traversal sequences, and ensuring all file operations use absolute paths with proper directory restrictions. Additionally, the application should sanitize input data to remove or encode potentially dangerous characters including null bytes and directory traversal sequences. Security measures should also include limiting file access permissions, implementing proper error handling that doesn't reveal sensitive filesystem information, and conducting regular security assessments to identify similar vulnerabilities in other components of the application. The vulnerability demonstrates the critical importance of proper input validation in preventing path traversal attacks and aligns with security best practices outlined in the OWASP Top Ten and other industry security frameworks that emphasize the need for robust input sanitization and secure coding practices.