CVE-2023-20091

A vulnerability in the CLI of Cisco TelePresence CE and RoomOS could allow an authenticated, local attacker to overwrite arbitrary files on the local file system of an affected device.

This vulnerability is due to improper access controls on files that are on the local file system. An attacker could exploit this vulnerability 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. To exploit this vulnerability, an attacker would need to have a remote support user account. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Weakness

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/27.html

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-roomos-file-write-rHKwegKf