Be Careful what you Scan for!

After some fun and games at one customer site in particular, I found that the SSL services on the earlier versions of the HP Proiliant Servers iLo ports (iL01 and iLO2) are not susceptible to heartbleed.

However, their implementation of SSL is fragile enough that scanning them for the Heartbleed vulnerability will render them inoperable.  This affects Proliants from G1 all the way up to G6, as well as many of the HP Bladesystems. 

A complete power down of the entire system - as in remove both of the AC cables - is required to reset the iLo card and bring it back to life.  While this may seem  like a quick fix for a single server, if that server is running a Hypervisor, or if it's a bladesystem with Hypervisors running on the blades, this can multiply to be a huge issue.  Especially if your client scanned the server subnet, and effectively bricked all their iLO cards before they realized there was a problem (oops)

(And yes, the fact that we worked this out Easter weekend is somewhat ironic.)

Full details are in HP Support Document c04249852

This illustrates that even when scanning for simple things (with NMAP, Nessus or any other scanning tool really), it's best to scan a few test systems first - or if you have a test VLAN that replicates your production systems, even better!   This isn't a problem with the scanners, almost always the problem is the fragility of the service being scanned.  Many services are only written to deal with "the right" inputs, which is not how most scanners (or most attackers) tend to operate.