Category Archives: Networking

Issues and news relating to networking.

The DIY drone that tracks your devices just about anywhere

Posted on by

The researchers behind an earlier version of Snoopy that tracked only Wi-Fi signals have already used it to track more than 42,000 unique devices during a single 14-hour experiment in 2012 at the King’s Cross train station in London. They have also unleashed Snoopy in a variety of other environments over the past two years, including at several security conferences. By taking careful notice of the Wi-Fi networks the devices have previously accessed (and continue to search for), the researchers were able to detect likely relationships among users. Four devices that hailed an SSID that the researchers geolocated to a London branch of one of the UK’s largest banks, for instance, were presumed to belong to coworkers of the financial institution.

via Meet Snoopy: The DIY drone that tracks your devices just about anywhere | Ars Technica.

This is why devices should default to wifi being off and only turned on when a user wants to use a public wifi.  Devices with wifi on will try and get an IP address via DHCP from any open wifi or wifi with a well known SSID — which can be spoofed by anyone.  This usually isn’t a problem.  The most they get is the layer 2 MAC address of the device which is unique.  This could be put into a database and used for tracking.

Sometimes devices will spill IP addresses through ARP requests  on networks they think they are still on and this can be problematic.

Alternative to Traditional Cellular Networks Makes a Virtue of Wireless Interference

Posted on by

Perlman says pCell takes a different approach: it embraces signal interference. In his vision, base stations smaller than your typical satellite TV antenna are placed wherever it’s convenient (such as on the roof or the side of a building), and their signals purposely overlap. Those overlapping signals, Perlman says, combine constructively to create a sort of personal cell, a centimeter in diameter, that moves with you as you move around the network. The signal doesn’t diminish as each additional user joins the network. Overall capacity can grow by adding more access points.

via Alternative to Traditional Cellular Networks Makes a Virtue of Wireless Interference | MIT Technology Review.

Stanford team tries for zippier Wi-Fi in crowded buildings

Posted on by

Meanwhile, the underlying tasks of assigning client devices to particular channels and access points are centrally controlled to make the best use of the infrastructure. Where separately owned and managed APs may make poor use of the unlicensed frequencies available in the building, the centrally controlled network can use its universal view to arrange the resources most efficiently.

via Stanford team tries for zippier Wi-Fi in crowded buildings – Network World.

Cellular’s open source future is latched to tallest tree in the village

Posted on by

And that network runs on open source. OpenBTS, an all-software cellular transceiver, is at the heart of the network running on that box attached to a treetop. Someday, if those working with the technology have their way, it could do for mobile networks what TCP/IP and open source did for the Internet. The dream is to help mobile break free from the confines of telephone providers’ locked-down spectrum, turning it into a platform for the development of a whole new range of applications that use spectrum “white space” to connect mobile devices of every kind. It could also democratize telecommunications around the world in unexpected ways. Startup Range Networks, the company that developed the open-source software powering the network, has much bigger plans for the technology. It wants to adapt the transceiver to use unlicensed spectrum for small-scale cellular networks all over the world without the need to depend on the generosity of incumbent telecom providers or government regulators.

via Cellular’s open source future is latched to tallest tree in the village | Ars Technica.

OpenBTS is a Unix-based software package that connects to a software-defined radio. On the radio side, it uses the GSM air interface used globally by 2G and 2.5G cellular networks, which makes it compatible with most 2G and 3G handsets. On the backend, it uses a Session Initiation Protocol (SIP) “soft-switch” or a software-based private branch exchange (PBX) server to route calls, so it can be integrated with VoIP phone systems.

ICANN seeks to tackle DNS namespace collision risks

Posted on by

For this “controlled interruption” JAS recommends returning an address within the 127/8 loopback range: “Responding with an address inside 127/8 will likely interrupt any application depending on an NXDOMAIN or some other response, but importantly also prevents traffic from leaving the requestor’s network and blocks a malicious actor’s ability to intercede.”

Instead of the familiar 127.0.0.1 loopback address for localhost, the report suggests “127.0.53.53”. Because the result is so unusual, it’s likely to be flagged in logs and sysadmins who aren’t aware of a name collision issue are likely to search online for information about the address problems.

via ICANN seeks to tackle DNS namespace collision risks – ICANN, Internet Corporation for Assigned Names and Numbers, gTLD, security, domain names – Computerworld.

Open Source Programming to the Software-Defined Network

Posted on by

Today, OpenDaylight is an open source platform for network programmability to enable SDN and create a solid foundation for Network Functions Virtualization (NFV) for networks at any size and scale. OpenDaylight software is a combination of components including a fully pluggable controller, interfaces, protocol plug-ins, and applications. The Northbound (programmatic) and Southbound (implementation) interfaces are meant to be clearly defined and documented APIs for network applications.

via OpenDaylight: Open Source Programming to the Software-Defined Network.

OpenDaylight delivered its first developer release, Hydrogen, on February 5th, 2014.

Home Routers Pose Biggest Consumer Cyberthreat

Posted on by

Of the small-office, home-office routers evaluated, every one could be compromised with relative ease by hijacking DNS connections, exploiting HTTPS flaws, weaknesses in Universal Plug and Play services, cross-site-scripting attacks, file-traversal and source-code vulnerabilities, weaknesses in WiFi Protected Setup (WPS), buffer overflows or simply bypassing authentication requirements.

via Home Routers Pose Biggest Consumer Cyberthreat.

During late 2013 and early 2014, gangs of Polish hackers have robbed thousands of consumers by attacking home routers and changing DNS settings so they point at the attackers’ DNS servers rather than legitimate servers.

DNS is a big problem.  Usually devices behind a SOHO router will receive their DNS info from the router via DHCP.  The router has been configured by the owner using DNS settings from their ISP or they could use one of Google’s servers like 8.8.8.8.  A user of their home network should expect a higher level of security unlike the open wifi people use on the road.

The simplest remedy is never allow router management access from the Internet.  This is usually turned off by default.  Routers should be set and forget so using the maintenance interface should be a rare occurrence.  The TP-LINK outlined here requires a user to click a malicious link while in a management session according to this:

Attack Requirements

  • The victim must have an active management session with the WR1043N.
  • The victim must be fooled in to performing an action (e.g., by clicking an attacker provided link), browse to a malicious or compromised site, or be the victim of a man-in-the-middle attack.

Here again the user gets tricked into becoming compromised so this wouldn’t be a problem if the user simply entered the management interface of the router, made changes, and left. There’s no point lingering around in a management session.

A physical dedicated firewall sitting between the Internet and treating all routers as dumb access points makes for an added layer of security.  All SOHO routers are relatively cheap embedded devices.  It is impractical to even expect them to defend against all possible exploits.  By virtue of being on the Internet everyone gets constantly scanned by bots.  That only poses a problem if the bot sees a vulnerability and phones home listing your device as a possible target.

CSEC used airport Wi-Fi to track Canadian travellers

Posted on by

Experts say that probably included many Canadians whose smartphone and laptop signals were intercepted without their knowledge as they passed through the terminal.

via CSEC used airport Wi-Fi to track Canadian travellers: Edward Snowden documents – Politics – CBC News.

The above statement is misleading.  A smartphone does not have  signals that can be “intercepted,” a smartphone actively seeks out and asks for an IP address so it can check in wherever some app wants to check in.  A lot of apps want to phone home and have access to a device’s network.  Smartphones are always active participants in a network.  The user of a smartphone has chosen to leave wifi active which means that user *wants* his device to scan for and connect to available bandwidth resources.  This scanning is a feature not a bug.

The document shows the federal intelligence agency was then able to track the travellers for a week or more as they — and their wireless devices — showed up in other Wi-Fi “hot spots” in cities across Canada and even at U.S. airports.

They simply store and key off the device ID or MAC address.  Every device has a unique MAC address, the layer 2 address used by local routers in the final leg of a route to send packets to the right device.  This address does not leave the local subnet unless through surreptitious means like a malicious app.

This kind of sweep probably captures browsing metadata all keyed by device id.  Not sure how useful any of that data will be to anyone.  End to end encryption using SSL can protect content of a message data but not metadata, the where and how long one communicates.  This kind of metadata could be useful nuggets in corporate espionage for all kinds of reasons.  If you’re just using the open wifi at the airport to pass time none of this matters as long as they’re not attempting Man In The Middle attacks or 0-day exploits against you.