CWE-73 (文件名或路径的外部可控制) — Vulnerability Class 437

CWE-73 represents a critical input validation weakness where applications allow external actors to dictate file system paths, potentially leading to unauthorized access or modification of sensitive data. Attackers typically exploit this vulnerability through path traversal techniques, injecting sequences like “../” to escape intended directories and reach critical system files or application configurations. This manipulation occurs when software fails to sanitize user-supplied input before using it in filesystem operations, allowing the attacker to bypass intended access controls. To mitigate this risk, developers must implement rigorous input validation, ensuring that all file paths are strictly checked against a whitelist of allowed directories. Additionally, using canonicalization functions to resolve paths before comparison and employing chroot jails can effectively isolate file access, thereby preventing attackers from navigating outside the designated application sandbox.