Cisco Security Responses

2017. október 31.

Cisco Smart Install Protocol Misuse

Cisco is aware of a significant increase in Internet scans attempting to detect devices where, after completing setup, the Smart Install feature remains enabled and without proper security controls. This could leave the involved devices susceptible to misuse of the feature. Customers who have not done so are encouraged to follow guidance in the Recommendations section of this notice to assess and ensure their network switches are properly protected against abuse of the Smart Install feature.

Several researchers have reported on the use of Smart Install (SMI) protocol messages toward Smart Install clients, also known as integrated branch clients (IBC), allowing an unauthenticated, remote attacker to change the startup-config file and force a reload of the device, load a new IOS image on the device, and execute high-privilege CLI commands on switches running Cisco IOS and IOS XE Software.

Cisco does not consider this a vulnerability in Cisco IOS, IOS XE, or the Smart Install feature itself but a misuse of the Smart Install protocol, which does not require authentication by design. Customers who are seeking more than zero-touch deployment should consider deploying the Cisco Network Plug and Play solution instead.

Cisco has updated the Smart Install Configuration Guide to include security best practices regarding the deployment of the Cisco Smart Install feature within customer infrastructures.

These issues have been reported by Tenable Network Security, Daniel Turner of Trustwave SpiderLabs, and Alexander Evstigneev and Dmitry Kuznetsov of Digital Security.

Cisco has recently published blog posts alerting our customers about the need to ensure their network switches are properly protected against abuse of the Smart Install feature, as Cisco has learned of a public posting that details potential abuse of this feature and has received reports of attacks when Smart Install was left enabled. These blog posts are available at the following links: