Monthly Archives: October 2016

Mirai, mirai on the wall

Update: Mirai now has an evil sister 

Mirai seems to be the talk of the town, so I can’t resist, I have to chime in.

Let me start by stating that last week’s Dyn attack was predictable.

But I think it is a mistake to single out one manufacturer when others demonstrably have the same issues. Both Axis and NUUO recently had full disclosure documents released that both included the wonderful vulnerability “remote code execution” – which is exactly what you need to create the type of DDOS attack that hit Dyn last week.

There’s not much we can do right now. The damage has been done, and the botnet army is out there, probably growing every day, and any script-kiddie worth their salt will be able to direct the wrath of the botnet towards one or more internet servers that that dislike for one reason or other. When they do, it won’t make any headlines, it will just be another site that goes offline for a few days.

The takeaway (if you are naive) is that you just need a decent password and HW from reputable sources. While I would agree on both on the principle -the truth is that in many cases it is useless advice. For example. if you look at the Axis POC you’ll see that the attacker doesn’t need to know the password at all. (I did some probing, and I am not sure about that now).

The impact?

The impact of this vulnerability is that taking into account the busybox that runs behind (and with root privileges everywhere. in all the binaries and scripts) is possible to execute arbitrary commands, create backdoors, performing a reverse connection to the machine attacker, use this devices as botnets and DDoS amplification methods… the limit is the creativity of the attacker.

And look, the affected cameras/encoders are based on BusyBox. A popular platform, and therefore a juicy target (see BashLite and ShellShock)

In other words:


I am not suggesting that Axis is better or worse than anyone else, the point is that even the best manufacturers trip up from time to time. It can’t be avoided, but thinking that it’s just a matter of picking a decent password is not helping things.

My recommendation is to not expose anything to the internet unless you have a very, very good reason to do so. If you have a reason, then you should wrap your entire network in a VPN, so that you are only able to connect to the cameras via the VPN, and not via the public Internet.

My expectation is that no-one is going to do that, but instead they will change the password from “admin” to something else, and then go back to sleep.

TileMill and Ocularis

A long, long time ago, I discovered TileMill. It’s an app that lets you import GIS data, style the map and create a tile-pyramid, much like the tile pyramids used in Ocularis for maps.


There are 2 ways to export the map:

  • Huge JPEG or PNG
  • MBTiles format

So far, the only supported mechanism of getting maps into Ocularis is via a huge image, which is then decomposed into a tile pyramid.

Ocularis reads the map tiles the same way Google Maps (and most other mapping apps) reads the tiles. It simply asks for the tile at x,y,z and the server then returns the tile at that location.

We’ve been able to import Google Map tiles since 2010, but we never released it for a few reasons:

  • Buildings with multiple levels
  • Maps that are not geospatially accurate (subway maps for example)
  • Most maps in Ocularis are floor plans, going through google maps is an unnecessary extra step
  • Reliance on an external server
  • Licensing
  • Feature creep

If the app is relying on Google’s servers to provide the tiles, and your internet connection is slow, or perhaps goes offline, then you lose your mapping capability. To avoid this, we cache a lot of the tiles. This is very close to bulk download which is not allowed. In fact, at one point I downloaded many thousands of tiles, which caused our IP to get blocked on Google Maps for 24 hours.

Using MBTiles

Over the weekend I brought back TileMill, and decided to take a look at the MBTile format. It’s basically a SQLite DB file, with each tile stored as a BLOB. Very simple stuff, but how do I serve the individual tiles over HTTP so that Ocularis can use them?

Turns out, Node.js is the perfect tool for this sort of thing.

Creating a HTTP server is trivial, and opening a SQLite database file is just a couple of lines. So with less than 50 lines of code, I had made myself a MBTile server that would work with Ocularis.


A few caveats : Ocularis has the Y axis pointing down, while MBTiles have the Y axis pointing up. Flipping the Y axis is simple. Ocularis has the highest resolution layer at layer 0, MBTiles have that inverted, so the “world tile” is always layer 0.

So with a few minor changes, this is what I have.


I think it would be trivial to add support for ESRI tile servers, but I don’t really know if this belongs in a VMS client. The question is time was not better utilized by making it easy for the GIS guys to add video capabilities to their app, rather than having the VMS client attempt to be a GIS planning tool.


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