Cisco confirmed that a Backdoor affects small business devices

8:30 ET, 14 January 2014

Cisco confirmed the presence of a Backdoor that affects small business devices. The flaw was discovered by the French hacker Eloi Vanderbeken weeks ago.

Cisco has recently disclosed (Advisory ID: cisco-sa-20140110-sbd) the presence of a backdoor in different small business networking devices, it is an undocumented Test Interface that could be exploited by attackers to access user credentials for the administrator account and the device settings. The vulnerability in Cisco Small Business Devices could be also exploited to send arbitrary commands to the device with escalated privileges.

“This vulnerability is due to an undocumented test interface in the TCP service listening on port 32764 of the affected device. An attacker could exploit this vulnerability by accessing the affected device from the LAN-side interface and issuing arbitrary commands in the underlying operating system. An exploit could allow the attacker to access user credentials for the administrator account of the device, and read the device configuration. The exploit can also allow the attacker to issue arbitrary commands on the device with escalated privileges.” states the official advisory.

The affected products are:

• Cisco RVS4000 4-port Gigabit Security Router running firmware version 2.0.3.2 and prior
• Cisco WRVS4400N Wireless-N Gigabit Security Router hardware version 1.0 and 1.1 running firmware version 1.1.13 and prior
• Cisco WRVS4400N Wireless-N Gigabit Security Router hardware version 2.0 running firmware version 2.0.2.1 and prior
• Cisco WAP4410N Wireless-N Access Point running firmware version 2.0.6.1 and prior

The vulnerabilities are still unpatched, but Cisco announced that a fix will be released soon (by the end of January 2014), the flaw is serious considering that there aren’t workarounds to fix the backdoor.

The French hacker Eloi Vanderbeken on his github page provided the exploit code for the Cisco Small Business Devices, in the past weeks I have posted an article to present his discovery of a backdoor in the main models of routers including Netgear, Linksys and Cisco.

Pierluigi Paganini

(Security Affairs –  CISCO small business devices, backdoor)