CVE-2023-20004: Overwriting Arbitrary Files with Cisco TelePresence CLI Vulnerabilities

Three vulnerabilities have been discovered in the command line interface (CLI) of Cisco TelePresence CE and RoomOS software, which could enable an authenticated, local attacker to overwrite arbitrary files on the local file system of an affected device. These vulnerabilities arise from improper access controls on files that are on the local file system. To exploit these vulnerabilities, an attacker would need to have a remote support user account.

In this article, we discuss the details of these vulnerabilities and how they can be exploited. We also provide information on the released software updates that address these issues and emphasize the importance of regular software updates and maintenance.

Vulnerabilities Details

The three vulnerabilities are due to improper access controls on files that are on the local file system. An attacker could exploit these vulnerabilities by placing a symbolic link in a specific location on the local file system of an affected device. A successful exploit could allow the attacker to overwrite arbitrary files on the affected device.

CVE-2023-20004

2. CVE-2023-20092 (note that this CVE does not affect Cisco DX70, DX80, TelePresence MX Series, or TelePresence SX Series devices)

Exploit

To better understand these vulnerabilities and how they can be exploited, let’s take a look at some sample code snippets and references. This specific exploit involves placing a symbolic link in a certain location on the local file system of the affected device.

The following code snippet is an example of creating a symbolic link on a Linux file system

ln -s /path/to/target/file /path/to/symlink

In this case, the attacker would replace the "/path/to/target/file" with the target file they wish to overwrite, and "/path/to/symlink" with the location they would like the symbolic link to be placed.

For more information on creating symbolic links and to understand how they work, please refer to this detailed guide:

Creating Symbolic Links in Linux

Fix and Recommendations

Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. It is highly recommended that Cisco TelePresence CE and RoomOS users apply the software updates provided by Cisco as soon as possible to protect their devices from potential attacks.

Please refer to the following Cisco Advisory for more information on the affected software and links to download the updates:

Cisco Advisory: Multiple Vulnerabilities in Cisco TelePresence CE and RoomOS Software

Conclusion

Regular software updates are necessary to ensure the security of any system. In the case of these Cisco TelePresence CLI vulnerabilities, applying the provided software updates as soon as possible should adequately address the issues. Regular maintenance and monitoring of software versions can help protect against such vulnerabilities and maintain the overall security of devices.

Timeline

Published on: 11/15/2024 15:23:29 UTC