Software Engineering Institute

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

TVT TD-2308SS-B DVR and possibly other models running firmware version 3.2.0.P-3520A-00 contain a directory traversal vulnerability. An attacker can use directory traversal to download critical files such as the config.dat file for the device which contains the credentials for the web interface. For example:
http://[IP ADDRESS]/../../../mnt/mtd/config/config.dat

This file can be parsed with the strings command to reveal the administrative user's plaintext credentials.

A remote unauthenticated attacker can download the configuration file of the device and use the obtained administrator credentials to access the web interface. The attacker may then modify the settings of the device and have access to the connected cameras.

We are currently unaware of a practical solution to this problem. Please consider the following workaround.

Restrict access to the TVT DVR interface

Restrict access to the TVT DVR web interface to trusted networks. If possible, configure management and transit networks for separate VLANs, or restrict access to the device using IP access lists.