CVE-2024-20450 - Critical Vulnerabilities in Cisco Small Business SPA300 and SPA500 IP Phones: Execute Arbitrary Commands with Root Privileges

Security researchers have discovered multiple vulnerabilities (CVE-2024-20450) in the web-based management interface of Cisco Small Business SPA300 Series IP Phones and Cisco Small Business SPA500 Series IP Phones. These vulnerabilities could allow an unauthenticated, remote attacker to execute arbitrary commands on the underlying operating system with root privileges.

This blog post aims to explain these vulnerabilities, provide code snippets, and link to original references for further detail on this issue. We'll also look at the possible exploit scenarios and potential impact if left unaddressed.

Vulnerability Details

The vulnerabilities exist because incoming HTTP packets are not properly checked for errors, which could result in a buffer overflow. An attacker could exploit these shortcomings by sending a crafted HTTP request to an affected device. A successful exploit could permit the attacker to overflow an internal buffer and execute arbitrary commands at the root privilege level.

Code Snippet

We have provided a very simple proof-of-concept here using the Python programming language, which demonstrates how the crafted HTTP request can exploit the vulnerability. We've removed some significant exploit details to avoid abuse by malicious actors.

´´´python
import requests
import sys

target_ip = sys.argv[1]

url = f"http://{target_ip}/management/"
headers = {

"User-Agent": "",

"Content-Type": "application/x-www-form-urlencoded"
}
payload = ""

response = requests.post(url, headers=headers, data=payload)

print(f"[*] Exploit failed on {target_ip}")

´´´

Original Reference

For detailed information about the discovered vulnerabilities, Cisco has released an official advisory that can be found here:

- Cisco Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20220223-spa300-spa500

Exploit Scenarios

Given the nature of the vulnerability, an attacker can exploit this issue without needing any authentication or special access, making it incredibly dangerous. Some possible exploitation scenarios include:

- Remotely taking control of the affected IP Phone, allowing the attacker to listen to or intercept calls.
- Launching a broader attack on the organization's network from the compromised IP Phone, potentially going unnoticed until significant damage has been done.

Potential Impact

The consequence of a successful exploitation can be disastrous for organizations relying on these devices to secure their communications as attackers may gain unauthorized access to sensitive information. Additionally, an attacker might use the compromised IP Phone to launch further attacks on an organization's infrastructure, potentially causing prolonged downtimes, data breaches, or even significant financial losses.

To mitigate these risks, it is strongly recommended that organizations using Cisco Small Business SPA300 Series IP Phones and Cisco Small Business SPA500 Series IP Phones keep their devices updated with the latest firmware from Cisco. Additionally, organizations should monitor their network continuously for any suspicious activity and ensure that appropriate access controls are in place to minimize the attack surface.

In conclusion, CVE-2024-20450 is a severe vulnerability that affects the web-based management interface of Cisco Small Business SPA300 and SPA500 IP Phones. It allows unauthenticated, remote attackers to execute arbitrary commands with root privileges. Organizations using these devices must take immediate steps to safeguard their networks by applying the latest updates and maintaining awareness of any signs of exploitation.

Timeline

Published on: 08/07/2024 17:15:50 UTC
Last modified on: 08/23/2024 18:14:43 UTC