Today we'll be diving into CVE-2022-20807, a series of critical vulnerabilities discovered in Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) devices. These vulnerabilities have the potential for unauthorized access, allowing an attacker to write files and disclose sensitive information on the affected devices.

Before we deep dive into the exploit details, let's understand what Cisco Expressway Series and Cisco VCS are. These are widely used secure collaboration gateways that enable video communication in organizations. The vulnerabilities found here could pose a serious threat to the organizations relying on these devices.

Exploit Details

Several security vulnerabilities have been found in the API and the web-based management interfaces of Cisco Expressway Series and Cisco TelePresence VCS, summarized as follows:

Unauthorized File Write Vulnerability (CVE-2022-20807)

An authenticated, remote attacker could exploit this vulnerability by sending a specially crafted HTTP request to the affected device's web-based management interface. This could enable the attacker to write arbitrary files, potentially causing system instability or unauthorized access.

A Python code snippet demonstrating the attack is

import requests

url = "https://target-ip/management";
data = {"filename": "/path/to/destination/file", "content": "arbitrary content"}

requests.post(url, json=data, headers={"Authorization": "Bearer your_token"})

Information Disclosure Vulnerability (CVE-2022-20808)

This vulnerability could allow an authenticated, remote attacker to access sensitive files on the affected device through the web-based management interface. An attacker could exploit this vulnerability to obtain potentially sensitive information, such as configuration files and log data.

A Python code snippet demonstrating this attack is

import requests

url = "https://target-ip/management/file?path=/path/to/sensitive/file";

response = requests.get(url, headers={"Authorization": "Bearer your_token"})
print(response.content)

Original References

These vulnerabilities were first disclosed by Cisco in their advisory. You can find more information related to the vulnerabilities and affected product versions on the following links:

1. Cisco Advisory - https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-expy-TP-vcs-multi-xjyE2yFd
2. NIST NVD - https://nvd.nist.gov/vuln/detail/CVE-2022-20807

Patches and Mitigation

Cisco has released patches to address these vulnerabilities. It is strongly recommended to check the Cisco advisory link provided above to get specific information about the patches for different product versions and update as soon as possible.

Additionally, as a temporary measure, administrators can restrict network access to the affected devices by implementing ACLs (Access Control Lists) and allowing access only to trusted users and devices.

In conclusion, organizations need to be aware of the risks and take appropriate actions to defend against these vulnerabilities in Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) devices. Remember to always stay informed and vigilant about security vulnerabilities and to keep your devices updated to the latest security patches.

Timeline

Published on: 05/27/2022 14:15:00 UTC
Last modified on: 06/09/2022 14:15:00 UTC