Tales from the Trenches: Vol 5 — Octet Dyslexia

Since 2004, RedSeal has helped our customers See and Secure their entire complex network. And while those customers may have understood the value of understanding their environment, how it was connected and see what’s at risk, there is often an “Aha” moment when the true significance is clear. The stories of these moments are lore within the walls of RedSeal. But these tales so clearly illustrate the value of RedSeal beyond just theory that we think they’re worth sharing. In the words of our team in the field, the ones working directly with our customers, this blog series will share the moments where it all gets real.

In this edition of the series, Bill Burge, RedSeal Professional Services exposes inconsistencies in policy definitions with RedSeal.

Octet Dyslexia

Numbers are a tricky business and more numbers equals more tricky, and sometimes our brains see what they want to see and not what is actually there.

While working on PCI audit prep using RedSeal Zones & Policies with a large manufacturer/distributor/retailer we were going over what Internet access existed from the Internet into their cardholder environment.

The customer had two external address blocks and some were allowed access through this path.

I’ll make up the address blocks, as 12.53.22.0 and 15.43.22.0.  In the table of access results was a block of inbound address that was 12.43.22.0 (or something like that).

I asked the customer about this external address block and they said “yeah, we have two external blocks”.  We did a few laps around this like the old “Who’s on first?” routine.

It wasn’t until I put a sample from this range along with samples from their two ranges that they were finally about to SEE that it was an amalgamation of their two ranges, just enough to fool the hurried mind.

A quick Whois determined that the range belonged to a Chinese university, IN CHINA.

We were able to use other features of RedSeal to determine all the device configurations that referenced this block and submit change requests to get them remediated.