[AusNOG] Bouncing Cisco Equipment and "Smart Install"

[Michael J. Carmody]

I just found it amusing that Cisco's wording is, it's bad, but it's designed to work that way.

Insecure by Design.

Sigh...

As a minor point of comparison, we do zero touch deployment for our VoIP handsets, but we basically scan the mac address of the pickingslip/side of box, then dump that into our provisioning system, which is advertised to the phones via DHCP option. This at least requires to be in the L2 broadcast domain to poke these.

This a routable L3 auto-configure, which strikes me personally, as incredibly stupid. But smarter heads than mine must know better.

-M

From: Michael Junek [mailto:michael at juneks.com.au]
Sent: Wednesday, 9 May 2018 2:27 PM
To: Michael J. Carmody <michael at opusv.com.au>; ausnog at lists.ausnog.net
Subject: Re: Bouncing Cisco Equipment and "Smart Install"


Hi Michael,



When I recently deployed a few 9300's in our DC, this feature was disabled before bringing in external connectivity because one of our engineers here was aware of this vulnerability and removed it.



It's enabled out of the box because the idea is that it's for zero-touch initial provisioning of the switch. The above engineer was working on a large infrastructure project for a govt department, which involved deploying approximately 600x 3850 switches. These were set up in a central system and when powered on, the configs were delivered, rather than having to console into every switch and deploy the configuration.



Michael







________________________________
From: AusNOG <ausnog-bounces at lists.ausnog.net<mailto:ausnog-bounces at lists.ausnog.net>> on behalf of Michael J. Carmody <michael at opusv.com.au<mailto:michael at opusv.com.au>>
Sent: Wednesday, 9 May 2018 14:21
To: ausnog at lists.ausnog.net<mailto:ausnog at lists.ausnog.net>
Subject: [AusNOG] Bouncing Cisco Equipment and "Smart Install"

Hey All,

Just a feeler to see if anyone else is seeing this.

We have some Cisco switches we use as Layer 2/3 NTU's to talk to client equipment on the far ends of fibre links.

As of yesterday morning, all of these switches started a roughly 1-2 hour reboot outage.

All smartnet'ed, running latest recommended stable from cisco, and nothing in the logs other than a hard reset just occurred.

We have been additionally hardening the exposure of various interfaces (attacks were captured coming from resi ISP looking .mx domains), and it appears the one that has stopped the rot is disabling the "Smart Install" feature with a "no vstack" command, reload config from out config store and back to work...

TBH I didn't even know this protocol existed... a non-authenticated, on by default protocol that allows you to configure and image deploy on network equipment.

Like, its our own fault, but what the hell is this doing on by default?

Anyone else with Cisco or "Smart Install" equipment seeing an uptick in scanning/poking activity?

-Michael Carmody

(Ref: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170214-smi )
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