CWE-24 (路径遍历：’../filedir’) — Vulnerability Class 91

CWE-24 represents a critical input validation weakness where software fails to properly sanitize user-supplied data before constructing file paths. Attackers typically exploit this vulnerability by injecting directory traversal sequences, such as "../", into input fields to manipulate the resulting pathname. This manipulation allows the application to resolve paths outside the intended restricted directory, enabling unauthorized access to sensitive system files, configuration data, or source code. To mitigate this risk, developers must implement robust input validation strategies that strictly whitelist allowed characters and reject any path components containing traversal sequences. Additionally, employing canonicalization techniques to normalize paths before validation ensures that encoded or double-encoded attacks are detected. Restricting file system access through chroot jails or containerization further limits the potential impact of successful exploitation, ensuring that even if validation fails, the attacker cannot escape the designated secure boundary.