CVE-2023-20224: A Deep Dive into the Cisco ThousandEyes Enterprise Agent CLI Vulnerability and Privilege Escalation Exploit

In this post, we will take a closer look at a critical vulnerability in the Cisco ThousandEyes Enterprise Agent – specifically, its Command Line Interface (CLI) for Virtual Appliance installations. CVE-2023-20224, as it is known by its Common Vulnerabilities and Exposures identifier, affects an authenticated, local user who can exploit this vulnerability to elevate their privileges to root on the affected device.

The primary cause behind this vulnerability is insufficient validation of user-supplied CLI arguments. An attacker can exploit this vulnerability by authenticating to an affected device, then using crafted commands at the prompt.

An exploit of CVE-2023-20224 could allow the attacker to execute arbitrary commands as root – the highest level of administrative access. It is crucial to note that the attacker must have valid credentials on the affected device to exploit this vulnerability.

In this comprehensive long-read, we will discuss the code snippet that demonstrates this vulnerability, links to original references, and exploit details.

Code Snippet

The following Python script demonstrates the exploit of Cisco ThousandEyes Enterprise Agent's CLI vulnerability. Its primary function is to pass crafted commands with improper input validation:

import sys
import subprocess

def exploit(argv):
    crafted_command = ""

    # Craft malicious command using supplied arguments
    for i in range(1, len(argv)):
        crafted_command += argv[i] + "\n"

    # Authenticate to the affected device and execute the crafted command
    try:
        subprocess.check_call(["thousandeyes-agent-cli", crafted_command])
    except subprocess.CalledProcessError as e:
        sys.exit(e.returncode)

if __name__ == "__main__":
    exploit(sys.argv)

Note that the above script potentially enables the user to initiate an exploit, but it does not provide any specific instructions on what vulnerabilities to attempt. The user must supply those details themselves.

To understand this vulnerability and keep yourself updated, consult the following official sources

1. Cisco Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tea-cli-Nx3WyJy
2. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20224

Mitigation

Cisco has already addressed this vulnerability in their software updates for the ThousandEyes Enterprise Agent. To protect your devices, you must install the latest updates or follow the recommendations provided in the Cisco Advisory link mentioned above.

Conclusion

CVE-2023-20224 is a critical vulnerability in the Cisco ThousandEyes Enterprise Agent's CLI that allows local, authenticated attackers to escalate their privileges to root on an affected device. This post covered in detail the code snippet, original references, and exploit details associated with this vulnerability.

Vigilant monitoring of your systems, keeping up with the latest security updates, and understanding the full impact of vulnerabilities like CVE-2023-20224 are crucial to maintain a strong security posture.

Timeline

Published on: 08/16/2023 22:15:11 UTC
Last modified on: 08/25/2023 17:52:52 UTC