Protecting against path traversal requires a "defense-in-depth" approach.
). Attackers often use encoding to bypass basic security filters that only look for literal characters.
The .. sequences navigate out of the pages directory, out of html , out of www , and out of var , landing in the root directory ( / ), ultimately loading the sensitive /etc/passwd file, which lists system users [1]. Risks Associated with This Attack Successfully exploiting this vulnerability can lead to: -include-..-2F..-2F..-2F..-2Froot-2F
: If not necessary, disable functionality that dynamically includes files based on user input. If you'd like, I can:
Example ModSecurity rule snippet:
Maintain a strict list of allowed filenames or characters. Reject any input containing dots ( . ), slashes ( / ), or encoded equivalents. Use Built-in Path Canonization
This payload attempts to perform two actions simultaneously: If you'd like, I can: Example ModSecurity rule
[User Input] -> `-include-..-2F..-2F..-2F..-2Froot-2Fsecret.txt` │ ▼ [Server Interpretation] -> /var/www/html/public/../../../../root/secret.txt │ ▼ [Final Resolved Path] -> /root/secret.txt
const path = require('path');