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Posts from the ‘Networking’ Category

13
Jun

Dome9 Package for Synology NAS

dome9_iconI own a Synology DS413j NAS, and without wanting to write a whole review about it, these things are awesome, the management UI is great, and you can run all kinds of packages on them. One thing I like to do with mine is run an OpenVPN server so that I can VPN into home and do cool stuff.

But I was a bit concerned about the notion of having my NAS internet-facing, even if it was only OpenVPN’s UDP port. So, powering through with my love for all things Dome9 (I swear they don’t pay me), I wrote my own little package that installs the Dome9 Agent onto a Synology NAS and allows you to control its firewall (and make dynamic access requests) through the Dome9 service. Now I can make pretty much any of my NAS’ services available to the internet, and not have to worry about random attackers discovering those services. Similar to Single Packet Authorization (although easier to set up and use), Dome9 allows you to dynamically open one or more ports to a given IP for a period of time, and so while the port is available to you, the services remain completely invisible to everyone else.

This is the first release of the Dome9 package, and while it may need more work to support other VPN protocols, it’s ready for testing. If you do use this package, I’d be keen to hear from you, as I’ve yet to find another Synology-owning Dome9 user!

To install this package, simply download the dome9.spk file (below) and use the Manual Install option in the Package Center in DSM. You will need to have a Dome9 account and enter your pairing key to allow the agent to pair with the Dome9 service.

Download: Synology Dome9 Package v0.1 (dome9.spk)

15
May

Honeyport Python Script with Local Firewall and Dome9 Support

Icon-PythonFollowing on from my linux bash honeyport script (read this first if you don’t know what a Honeyport is), I wanted to write a script that works across platforms to accept connections on a given port and block that IP using the local firewall – IPFW on Mac OS X, iptables on Linux, or Windows Firewall – or using the Dome9 service (I’m hoping to add Unix support soon).

I chose to write this one in Python as the cross-platform language of choice, and it’s compatible with Python 2.7 to 3.4. One feature of this script is that you can optionally configure it to run another Python script whenever a client connects to the honeyport. The client’s IP will be passed to the called script as an argument, allowing you to do whatever you want with it. The script’s output is then sent back to the connected client before they are blacklisted.

Check it out on GitHub, improvements and additional ideas are welcome!

21
Aug

Linux Bash Ncat Honeyport Script with IPTables and Dome9 Support

After securing systems by hiding them completely from the network/internet using Single Packet Authorization, I’ve recently been interested in doing more so-called ‘active’ defense, by implementing solutions to delay, confuse, or thwart attackers. Completely hiding one’s system is not always feasible (ie. in the case of an internet-facing server), and monitoring, apart from being purely reactive, is not always easy and requires the involvement of a human. An alternative to these is to do some automated active defense. One simple tool in the bag of active defense tricks is the honeyport. Read moreRead more

11
Oct

WebKnock.org: An fwknop SPA web-interface

Vasilis Mavroudis has launched WebKnock.org, a web-based front end to the fwknop (Single Packet Authorization) client. It does not yet seem to support the full suite of fwknop features, but the WebKnock site allows you to send basic auth packets to your fwknop server in order to open firewall ports. This can definitely come in handy if you need access to a port on your server, and don’t have the fwknop client handy on the computer, Android or iPhone (coming soon).

Note that although WebKnock uses SSL to protect the HTTP session, you are required to supply your fwknop password. If logged or intercepted, your knock details could be used to open firewall ports or even run commands on your server (depending on how you’ve configured fwknop). While WebKnock may be useful in a bind, from a purely security standpoint I don’t recommend using it regularly due to this risk. If you do use it, you should consider changing your fwknop passphrase.

I hope that WebKnock is eventually open-sourced to allow both for the code to be reviewed, and for people to host their own instance of WebKnock. It would also be nice to see more fwknop features being added, including the ability to define a username, and open multiple ports at once (eg. by entering: tcp/22 udp/53 tcp/80). The ‘Allow IP’ field should also get pre-populated with the visitor’s IP address for convenience.

Source: Cipherdyne

8
Sep

Reverse SSH over Tor on the Pwnie Express

The Pwnie Express (PwnPlug) is a great little tool for hackers, pentesters and social engineers alike. While I don’t advocate the use of a Pwnie for illicit purposes, I was intrigued about using it as an untraceable tap into a network. Out of the box the Pwnie allows you to configure reverse SSH connections, exfiltrated over a number of different protocols including HTTP, SSL, ICMP and DNS.

While these are great for getting out of controlled networks, they all require the Pwnie to be configured with the IP address of your SSH server, which could potentially be traced back to you. It also requires your SSH server to be able to directly receive connections at the IP/hostname configured on the Pwnie. While one could run an SSH server on a proxy box somewhere, I felt that was too primitive, so I installed Tor on my Pwnie and configured a Tor Hidden Service on my SSH server.

Note: For the purposes of this tutorial, the SSH server will be running on BackTrack 5. I’m assuming you’ve already performed the initial Pwnie Express setup steps on the server! Check out my PwnieScripts to help speed up and automate the Pwnie setup.

These instructions do not yet work on Pwn Plug software >= 1.1 as they’ve changed the layout of things! Will update this post when I get the time.

Read moreRead more

1
Sep

Kernel.org Compromised, OpenSSH Source Not Backdoored

Kernel.org, the primary site for the Linux kernel source, was compromised sometime in August. It is believed that the attackers gained access using compromised user credentials, and then escalated their privileges to root. Early pieces of information implied that some OpenSSH source code was stored on the compromised Kernel.org server(s), apparently this may not be the case. So far the investigation has found that several modifications were made to the compiled OpenSSH client and server binaries running on the system to log user activity. The full extent of the changes is not yet known, and nobody has yet come forward to claim this hack.

If you’ve installed or updated your kernel or OpenSSH recently, you may want to reinstall from a known good version, although it is not yet known if any kernel sources were modified. Although in this case OpenSSH wasn’t compromised, admins can consider running some form of Single Packet Authorization, such as fwknop, as an additional layer of protection for your SSH server against these kinds of issues (backdoors) and other potential future 0days.

Hopefully more info will come to light as the investigation progresses. Hit the jump for more details.

Read moreRead more

10
Jun

Locate Lost or Stolen Macs with ‘Find My Mac’ in Lion and iCloud

Apple’s popular Find My iPhone feature of MobileMe is being extended to Macs as well, as part of iCloud and Lion (10.7.2). It will also allow the person who found or stole the machine to login using a limited guest account (with only access to Safari), in order to allow your Mac to connect to the internet. As with the iOS version, Find My Mac will allow you to remotely send a message, lock or even wipe your computer.

I’m guessing the geolocation will be limited to triangulating local wireless networks, but I’m hoping it will also send back the public IP address of the network it’s currently connected to, which would help significantly when trying to recover a stolen device. I wonder how developers of commercial Mac tracking software are feeling right about now?

For more info and pictures check out this post at Cult of Mac. In other news, iOS 5 will finally bring the ability to delete entries from your call history.

14
May

Fwknop in BackTrack 5 Repository

Just a quick update to say that fwknop (Single Packet Authorization tool) has made it into the BackTrack 5 repository. Although it’s not installed by default, it’s a few keystrokes away, and can be installed by typing the following into the terminal:

apt-get install fwknop-client

apt-get install fwknop-server (if you want to use the server on your BackTrack install)

Note that it’s still version 1.9.12 of the Perl implementation, as the the C++ port (v 2.0) is still in the Release Candidate stage. Those of you who have been meaning to experiment with Single Packet Authorization and have already downloaded BT5, now’s a good time to install fwknop and give it a try! When installing fwknop-server it brings up an ultra-simple config screen that allows you to set up your initial passphrase.
Read moreRead more

4
Feb

Single Packet Authorization with simpleSPA

I was just made aware of simpleSPA, a recently-released Java implementation of Single Packet Authorization by Chris Chrysler. The package provides a Linux-only server-side daemon, and a Linux and Windows client. Although I haven’t testing it yet, I assume the client will also work on Mac OS X. This implementation requires a Linux server as it relies on iptables being the firewall. simpleSPA uses two RSA keys in order to encrypt the authentication information. The first key encrypts the username of the user requesting access, while the second key is used to encrypt a pre-shared key and a timestamp (for freshness). The resulting authorization packet is then sent via UDP to the server. Although a timestamp is used, there doesn’t appear to be an explicit check for previously-received packets (ie. using a hash), so there may be some for time-limited replay attacks. Because RSA and public-keys are used, it’s a shame to see that it doesn’t use digital signatures to protect the payload.

simpleSPA does not allow for dynamic configuration of the firewall. As such, upon receiving a valid authorization packet (using Jpcap to sniff the wire), the server looks at a pre-defined config file that defines the firewall port(s) to be opened for the requesting user. Furthermore the port is opened for the IP that made the request, thus not allowing the client to embed an IP within the request and open a port out-of-band. The author states that this implementation is primarily an academic proof-of-concept at this point, and so is nowhere near as complete as other implementations such as fwknop (Perl/C) and Aldaba (C). It is nice, however, to see continued research and development into SPA as well as a Java implementation!

15
Dec

OpenBSD IPSec Possibly Probably Not Backdoored by FBI

In a post to the OpenBSD mailing list, developer Theo de Raadt reveals an email from an ex-contributor (Gregory Perry) alleging that money was accepted from the FBI around 2000-2001, in return for implementing a backdoor into the IPSec stack. Such a backdoor would give the FBI the ability to eavesdrop on any IPSec connection made using OpenBSD, or any other projects that have since made use of its IPSec code.

Clearly this would be a big deal if true, and although we know that open source projects are regularly backdoored by rogue developers or ‘hackers’ (such as the recent ProFTPd backdoor), it is not often that we hear of governments inserting some themselves. Should we be surprised? After all it is known that the NSA was involved with the development of DES by altering the algorithm’s S-Boxes and suggesting a shorter key length. There are also rumors of a covert backdoor in several versions of the Windows OS. That said, many people are smelling a troll in this case.

Following this information (can we call it a leak rumor?), OpenBSD’s IPSec code will undoubtedly come under quite a bit of scrutiny, and I’m sure we will hear a lot more about it should anything untoward be uncovered.

Read the full mailing list post here, archived below for posterity.

[Update] Scott Lowe denies being affiliated with the FBI, and Jason Wright denies having inserted a backdoor. This is sounding more and more like a trolling. To what end, I couldn’t speculate. It’s also worth noting that this kind of activity would probably not fall under a normal NDA, but under a government-level Top Secret classification which lasts at least 25 years…

An interesting observation about OpenBSD IPSec and Stuxnet. Read moreRead more

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