: If an attacker can "include" a file they have previously uploaded (like a log file containing malicious scripts), they may execute code on the server.
: Never trust user input. Use a "whitelist" approach—only allow specific, known-good characters (like alphanumeric characters) and reject anything containing dots or slashes. -include-..-2F..-2F..-2F..-2Froot-2F
: Modern WAFs are designed to detect and block common attack patterns, including URL-encoded traversal sequences like -2F..-2F . Conclusion : If an attacker can "include" a file
If the back-end code takes that page parameter and plugs it directly into a file system call without checking it, an attacker can swap contact.html with our keyword string. The server might then attempt to "include" a sensitive system file, such as /etc/passwd , and display its contents to the attacker. The Risks of Improper File Handling A successful traversal attack can lead to: : Modern WAFs are designed to detect and