Yesterday Google Scholar sent me another alert about a new paper. I must say that Google Scholar is becoming my number 1 source to stay up to date about research in mobile security.

The paper, “Formal analysis of 5G authentication“, is a pre-print released by  a team from ETH Zurich, University of Lorraine and University of Dundee. Similarly to a recent paper on LTE security (LTEInspector: A Systematic Approach for Adversarial Testing of 4G LTE), the authors translate the 3GPP protocol specifications into pseudo-code that can be formally verified and analyzed. In this case, the authors analyze the recently released 5G 3GPP specifications, with special focus on the authentication protocols. To do so, the authors use Tamarin, a protocol verification tool.

I strongly recommend reading the paper. As I expected, the authors found a few weaknesses on the protocol. The 5G AKA protocol appears to fail to meet several security goals that are explicitly required by the 3GPP specifications, as well as other critical security properties. The paper highlights weaknesses in the standard and suggests improvements and refinements. Such an interesting work and an excellent paper.

It is worth noting that a couple months ago I was invited to write an opinion article on 5G security and I got some criticism from 3GPP folks on it, claiming that 5G is secure and things have been improved very much. As I stated in my article (Are we there yet? The long path to securing 5G mobile communication networks), I still see a long way to go to fully secure mobile communication networks. And the new sophisticated security architecture and PKI infrastructure are very interesting, but based on the unrealistic assumption that each SIM will have a public key or certificate for all operators from all countries. I always acknowledge that it is very hard to achieve a secure mobile communications system and the only reason I work in proactively identifying security weaknesses is to keep raising awareness on this problem.

It makes me happy to see so much excellent work coming from academia in the area of mobile security. Excellent research topic for talented PhD students to work on. And it makes me even happier that, just a couple of months after being publicly released, there is security research analyzing the 5G specifications. I am myself currently involved in a research project on 5G security with a team from VATech under Prof. Jeffrey Reed and Prof. Vuk Marojevic. We are working on a new paper on 5G security that should be out sometime later this summer or early Fall. Stay tuned! For the ones of you who saw me speak at UC Irvine last May or at Hushcon East in NY in June, you already got a bit of a sneak peak.

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Yesterday, Google Scholar sent me an alert of a paper I might be interested in. It turns out, I am indeed very interested in it. This is a paper already accepted, in its new rolling window review process, for the IEEE Security and Privacy symposium of 2019 (link for this year’s symposium): Breaking LTE on Layer 2.

There is no available pre-print yet, but there’s an abstract already:

Long Term Evolution (LTE) is the latest mobile communication standard and has a pivotal role in our information society: LTE combines performance goals with modern security mechanisms and serves casual use cases as well as critical infrastructure and public safety communications. Both scenarios are demanding towards a resilient and secure specification and implementation of LTE, as outages and open attack vectors potentially lead to severe risks. Previous work on LTE protocol security identified crucial attack vectors for both the physical (layer one) and network (layer three) layers. Data link layer (layer two) protocols, however, remain a blind spot in existing LTE security research. In this paper, we present a comprehensive layer two security analysis and identify three attack vectors. These attacks impair the confidentiality and/or privacy of LTE communication. More specifically, we first present a passive identity mapping attack that matches volatile radio identities to longer lasting network identities, enabling us to identify users within a cell and serving as a stepping stone for follow-up attacks. Second, we demonstrate how a passive attacker can abuse the resource allocation as a side channel to perform website fingerprinting that enables the attacker to learn the websites a user accessed. Finally, we present the A LTE R attack that exploits the fact that LTE user data is encrypted in counter mode (AES-CTR) but not integrity protected, which allows us to modify the message payload. As a proof-of-concept demonstration, we show how an active attacker can redirect DNS requests and then perform a DNS spoofing attack. As a result, the user is redirected to a malicious website. Our experimental analysis demonstrates the real-world applicability of all three attacks and emphasizes the threat of open attack vectors on LTE layer two protocols.

It is always great news to see excellent security research on LTE published that is based on open source implementations of the LTE stack. This is something I anticipated a few years ago. I am also very familiar with the work of this new paper’s authors. They have worked on some really interesting security research work on LTE and I have discussed some of their most recent papers in this blog.

This new paper is particularly exciting because it seems to build up on some of my work from a few years ago. Based on the abstract (“we first present a passive identity mapping attack that matches volatile radio identities to longer lasting network identities, enabling us to identify users within a cell and serving as a stepping stone for follow-up attacks), it sounds like they are implementing RNTI-based user tracking and using it for what sounds like a series of new really interesting attacks against LTE. I really look forward to reading the paper and learning more about the excellent work they did and the new protocol exploits they found.

Back in 2016 I presented at ShmooCon (slides and video) and published a paper discussing and implementing Denial of Service attacks against LTE, IMSI catchers on LTE and, relevant to this new paper, presenting and implementing in a real network for the first time a user location tracking attack leveraging the PHY layer id known as RNTI (Radio Network Temporary Identifier). For details, see slides 31 to 44 here and section V.F of my paper from 2016.

In a nutshell, the RNTI is an id derived and assigned in the RACH handshake in plain text (and thus can be easily captured with a simple LTE downlink sniffer such as AirScope from Software Radio Systems). It is included in plaintext in the header of every single PHY layer packet, which means that it is included in the plaintext in all uplink and downlink packets of a connection. As such, it can obviously allow to distinguish traffic flows from multiple users and track a given user, if one can map the RNTI to something else. As I implemented in my work a couple years ago, mapping the RNTI to the TMSI or even the MSISDN (the phone number of the user) is trivial. Once one maps an RNTI to a TMIS, then one can leverage paging messages to further expand the ability to track a user, as Kune showed in a really cool paper from a few years ago. I also recently read a paper that expands even further the ability of user tracking on LTE by using the GUTI.

A couple of years ago I also demo-ed at HackerHalted an implementation of an RNTI-based tracker running passively using a modified version of srsLTE and a USRP radio (see slides here).

The authors of “Breaking LTE on layer 2” seem to have implemented and tested the RNTI tracking techniques in their paper and used it as the stepping stone for new attacks that sound pretty cool and interesting, given what the abstract reads. Hopefully we don’t have to wait until IEEE S&P 2019 (May 2019) to learn more details on their new research. Knowing the excellent work that this authors have published in the recent years, I expect a very good paper that is likely to generate a lot of conversations and discussions. The more work in this area the better, as we need people talking about this and actively working in making mobile networks more secure. Really looking forward to reading their paper!

Related published work on user tracking and, specifically, RNTI tracking:

[1] Jover, Roger Piqueras. “LTE security, protocol exploits and location tracking experimentation with low-cost software radio.” arXiv preprint arXiv:1607.05171 (2016).

[2] Jover, Roger Piqueras. “LTE security and protocol exploits.” Shmoocon 2016 (2016).

[3] Hong, Byeongdo, Sangwook Bae, and Yongdae Kim. “GUTI Reallocation Demystified: Cellular Location Tracking with Changing Temporary Identifier.” In Symposium on Network and Distributed System Security (NDSS). ISOC. 2018.

[4] Kune, Denis Foo, John Koelndorfer, Nicholas Hopper, and Yongdae Kim. “Location leaks on the GSM air interface.” ISOC NDSS (Feb 2012) (2012).

[5] Jover, Roger Piqueras. “Some key challenges in securing 5G wireless networks.” Electronic Comment Filing System, Jan(2017). [PDF]

 

UPDATE (06/28/2018) – The authors have released a web site describing their findings and, more importantly, including a pre-print of the paper. As I had guessed, this is indeed based on my RNTI tracking techniques. The authors leverage those techniques to fingerprint web traffic and, despite being encrypted, they can estimate who browses what websites. They test this with a bunch of top 50 Alexa sites. The other new attack, aLTEr, is very interesting. By exploiting the fact that certain layer 2 messages are encrypted but not integrity checked, they flip bits in the cipher text in a very smart way to modify the destination IP fr DNS queries, effectively redirecting any mobile device to, for example, a malicious domain when they believe they are browsing a legitimate service.

The paper seems to indicate that I did not test and implement RNTI tracking a couple of years ago, but I actually did. And also showed a demo at HackerHalted in Atlanta back in 2016. Regardless, this new paper is excellent, and worth a read. Check out the references, as they link to some of the working documents from GSMA and 3GPP  after receiving the authors’ disclosure about this protocol exploits. Interesting, though, that #GPP and GSMA seems to only be concerned about the aLTEr exploit and not really worried about the other one (see S3-181429 document from the 3GPP TSG SA WG3 Security Meeting #91).

I was reading this report this morning and I must confess that I was not surprised. Long story short, many devices out there running Android have ADB actively listening on port 5555, essentially leaving those devices out there exposed with a nice and convenient sudo backdoor.

Android’s Debugging Bridge is a tool that allows communicating with a device, execute commands and, essentially, fully control the device with a sudo shell-like terminal. It is not authenticated or secured, but in order to use it, one must have physical (USB connection) to the device and manually toggle Debug Mode on the phone. This makes this backdoor on an Android device at least hard to access by an adversary. However, it has been discovered that many devices out there allow access to ADB via the network simply by connecting to port 5555.

It is not surprising that, as a result, there’s been a massive spike in port-scanning of port 5555 recently. And so far researchers discovered already a malware/botnet that exploits this to mine cryptocurrencies on Android devices.

1_x5IpPUs3qt6r23yE3jF0BQ

So far it’s a botnet mining bitcoin, but the worst case scenario of a sudo backdoor on an Android device is pretty bad. It will be interesting to learn more about what types of devices this is affecting. According to the report, they have found “everything from tankers in the US to DVRs in Hong Kong to mobile telephones in South Korea. As an example, a specific Android TV device was also found to ship in this condition.

ADB open listening to port 5555, what could possibly go wrong?

(Originally posted as an article on LinkedIn)

The mobile and wireless communication industry is highly susceptible, as are most sectors in the information technology industry, to drowning in a sea of buzzwords. “5G” is a concept that has been thrown around frequently for the past 6 years or so to define a futuristic – and potentially hard to achieve – connectivity scenario in which speeds of 1Gbps are ubiquitous, sub-10ms latencies are the norm, and the network can take on 1,000 times more connected devices without any hiccups. This utopian connected world has always been promised to arrive in 2020, to coincide with the Tokyo Summer Olympics, with the first trials during the 2018 Winter Olympics.

While the buzz around 5G has spawned conferences, workshops, symposiums, industry consortiums, and tomes of scientific press, some great minds in both academia and industry have been working on actual technology which, unlike big stands at expos and conferences and flashy slide decks, will solve the 5G connectivity challenges. mmWave communications are the clear path towards being able to achieve gigabit rates ubiquitously in dense urban scenarios and, although radio signal propagation is very challenging at such high bands, massive MIMO (Multiple-Input Multiple-Output) and adaptive beamforming arrays are the promising technologies that will help close that gap.

While 5G has mostly been a buzzword attached to flashy presentations and keynotes during the last few years, this does not change the fact that there have been outstanding research and development advances in some of the key technology areas that will sustain the connectivity demands of the next decade. That is, things that will make the concept of 5G an actual reality. As a result of this excellent work, the first official release of the 3GPP standards for 5G communication systems was published in December 2017. The new proposed mobile communication system is known as New Radio (NR) and its Core Network (as opposed to the Radio Access Network) is known as 5G System (5G-S).

While the technology pillars for future 5G mobile systems were being developed, there has been a spike in excellent security research work in the general field of mobile communications, and LTE mobile networks more specifically. As I anticipated 2 years ago, open source platforms have provided the perfect tools for bright security researchers to work on outstanding research projects that have yielded the discovery of all sorts of implementation issues and communication protocol deficiencies in LTE mobile networks. In some cases, the technology press has picked up on some of the resulting scientific publications at top conferences, which has sent shockwaves throughout the mobile communications industry. Such great research has also driven security innovation and protocol improvements that are making mobile networks nothing but more secure and resilient.

For quite a few years, I have been among the advocates for piggybacking on the technology disruption of 5G to address the well-known and, in many cases, very concerning security and scalability issues in LTE mobile networks. Although the major breakthrough in 5G will be at the physical layer (PHY), we are long overdue on reconsidering the current circuit-switched architecture of core mobile networks and embracing a fully packet-switched architecture. Although the mobile core of LTE is already fully IP-based, the architecture of the network still heavily relies on circuits – known as bearers in 3GPP jargon – and complex state machines. Among many other reasons for embracing a packet-switched architecture, the goal of massive connectivity in 5G networks will never be achieved in current control plane signaling-constrained networks. This is especially true when the goal is achieving connectivity for 1,000 times more devices and the Internet of Things (IoT) is at our doorstep, waiting to enter the game. As a great point of reference for this massive challenge in mobile networks, I always like to refer my colleagues to the visionary paper by J Kim and Paul Henry.

In general, the disruption of 5G is indeed the perfect opportunity for major architectural changes in the core network, though this is a challenging goal. However, it would be a big loss if, at the very least, 5G was not used to address the minor, and narrower in scope, changes required to tackle concerning security exploits uncovered in LTE. By now, it is well understood that there are multiple ways an adversary could abuse the pre-authentication Radio Resource Control (RRC) and Non-Access Stratum (NAS) messages, both of which are neither authenticated nor encrypted. As such, LTE mobile networks and, more importantly, LTE smartphones and network equipment, are potentially vulnerable to certain privacy leaks and Denial of Service (DoS) attacks, as prototyped in the lab by several research projects over the last 5 years.

The first release of the NR and 5G-S standards (Release 15 of the 3GPP standards), with the initial specifications released in December 2017, makes a partial attempt at addressing such security issues. Interestingly, most of the security definitions have not been included in the specifications until the updated documents released in March 2018. There are some ongoing efforts in protecting the International Mobile Subscriber Identifier (IMSI) using Public Key Infrastructure (PKI), likely motivated due to the recent amount of press and media coverage on IMSI catchers, in addition to leveraging PKI to authenticate certain pre-authentication messages. However, it is still to be seen how certain challenges, such as how to authenticate or implement PKI with a subscriber roaming from another network – or even a foreign network – will be solved. There are also several edge cases in which null integrity and null ciphering are used, such as the initial registration procedure for emergency services (3GPP TS 24.501 V1.0.0 2018-03 – 4.4.2.1). Plus, the fact that null ciphering and null integrity are supported (3GPP TS 24.501 V1.0.0 2018-03 – Table 9.8.3.29.1) could potentially end up in insecure, unexpected protocol edge cases. Besides that, the sheer number of pre-authentication messages still exposes protocols to potential security exploits.

I recently collaborated with a highly-renowned mobile security research team from academia (Prof. Jeffrey H. Reed and Dr. Vuk Marojevic at Wireless @ Virginia Tech) in a security analysis of the NR standards. In the past, both that team and I had been involved in research on protocol-aware jamming and the underlying vulnerability of LTE mobile networks to adversarial RF jamming. The goal of this latest security analysis was to investigate the feasibility of protocol-aware jamming in the proposed PHY layer in NR. The outcome of the study will be presented in the 1st IEEE Workshop on 5G Wireless Security coming up this May in Kansas City, but the results are already available to the public in our paper.

Although the outcome of the security analysis is not encouraging, one must acknowledge that it would have been a massive achievement to simultaneously tackle the challenge of gigabit connectivity, mmWave combined with massive MIMO and, on top of that, security and resiliency. Things at the higher protocol layers still look rather challenging as well. Despite my forays into PHY layer security and protocol-aware jamming, most of my security research work over the last 8 years has focused on protocol-level exploits on various wireless technologies, with great focus on 3GPP’s LTE as defined starting on Release 8. As one of the few researchers who has uncovered numerous protocol exploits that would result in DoS of mobile devices and privacy leaks, I was, and still am, optimistic about the role of 5G disruption in enhancing the security of mobile networks. And leveraging PKI is definitely a step in the right direction.

Nevertheless, what we have seen so far in the NR and 5G-S standards is not a complete solution yet, despite attempts to address protocol exploits. In parallel, there is also a set of new pre-authentication messages and new fields and configurations in existing messages. One must acknowledge, though, that fully securing mobile communication networks is a massive challenge that will require collaboration among academia, industry and researchers.

As a security researcher, many of my colleagues and I see the emerging landscape of 5G as a blank canvas to experiment with the potential security impact of adversarial tampering, spoofing and intercepting of these pre-authentication messages in NR and 5G-S. And it is critical that the security research community and the mobile communications industry work together in identifying such potential exploits and, more importantly, their root causes, so the security of the upcoming 5G networks can be enhanced in short order. There is still time until 2020 to enhance mobile communication networks even further.

Although we could – and perhaps should – be much closer by now, there is still a very long way to go to fully secure mobile communication networks. The same applies to reaching a flexible and truly scalable mobile architecture capable of supporting the connectivity demands of the future. However, the very active community of mobile security researchers will hopefully take us to that stage.

Equipped with an army of software radios, mostly USRP B210s, and my new toolset based on srsLTE, I continue my work on protocol-fuzzing mobile and wireless network standards with the goal of contributing to the security of the communication systems used by billions on a regular basis. In my case, time is now slightly scarcer due to my recent fatherhood. But, I continue to work and follow closely the excellent work of the few other teams in this research field, where outstanding graduate students and researchers are paving the way towards secure and reliable mobile communication networks.

This time, I cannot predict whether there will be a large number of new security exploits identified and prototyped in NR and 5G-S networks in the near future or a spike in mobile security findings in this field, mainly because there are no available test-beds or open source implementations of the Release 15 stack. But, as long as the folks behind tools such as srsLTE keep up their great work, it will not take long for the right tools to be available for applied security research on 5G mobile systems. And when that day comes, it is game on!

Roger Piqueras Jover is a Security Architect in the Office of the CTO at Bloomberg, where he is actively engaged in mobile and wireless security research. He maintains a bibliography of his previously released and published work at his personal website: http://rogerpiquerasjover.net.

I have mentioned in the past how I follow closely the work of Prof. Seifert‘s lab in TU Berlin. They are the source of some of the most interesting security research over the last few years. The lab has been around long enough that their alumni are now around working in more interesting research.

The latest results from an alumni from that lab are the remote code execution exploits identified by Nico Golde in his most recent article. A series of implementation errors on the code that handles emergency broadcast notifications result in an integer underflow. This combined with a lack of bounds check, results in the remote code execution exploit. There are some challenges, such that the time window to execute the exploit is of about 5 seconds but, other than that, this is a rather interesting one. Apple already patched the issue, so this is now mainly a very interesting research work.

Despite the very interesting exploit documented by Nico, my favorite part of the article is the detailed analysis of the 3GPP and ETSI standard documents presented. It is a great illustration of very large and challenging problems in the world of standards in general. Standards often end up being incomplete due to the complexity of reaching an agreement among such a complex and heterogeneous set of stakeholders from the industry with different requirements and goals. On top of that, technology itself often poses a major challenge that, due to the complexity of finding an optimal solution, is just ignored or a less secure way around is chosen.

The article focuses specifically on the Public Warning System, the system that piggybacks on the paging channel (PCH) and cell broadcast channels in order to provide disaster warnings to the population in semi-real time. Providing security and authentication for such a system is very complex, mainly because, although an operator could cryptographically sign disaster alert broadcast messages, users roaming to a foreign network would have no means of verifying and decrypting (if necessary) such messages. As such, the choice in the standards was to simply leave security “out of the scope of the 3GPP specifications“. Despite everyone acknowledges that finding a solution is very challenging, leaving security out of the scope of a standard document is not rare.

etws_security1

3GPP TS 22.268 Release 11 – Page 9

By means of reverse engineering the code of Intel’s XMM7360, the cellular baseband used in all modern iPhones, the author was able to identify a combination of integer underflow and lack of bounds check that results in potential remote code execution for devices with iOS prior to 11.3.

Very interesting work that follows up on their previous research on cellular baseband exploitation. Good read!

I often find myself wondering “what could possibly go wrong?” sarcastically when I read about hotel doors that can be unlocked via BLE with an app and all other sorts of products with BLE connectivity. Being familiar and hands-on with the well known security issues of BLE are actually sometimes very useful. I once got a huge discount on an AirBnB stay after I demo-ed a hack on the host’s cute Catskills house’s smart lock, an August smart lock, and helped the host update the app and firmware. All credit to Jmaxzz for the excellent work presented at DefCon, which I simply partially reproduced.

In general, I always tell folks that it is never a good idea to use BLE for connectivity if you are building a product with high security requirements. That’s why, the moment I read about a smart credit card that uses BLE, my first thought was – yes, you guessed it right – “what could possibly go wrong?”. And Mike Ryan made my day with a blog post explaining precisely what could go wrong and, indeed, what did go wrong.

Mike Ryan is possibly the most well known Bluetooth security researcher out there. He is the author of one of my favorite tools, Crackle, which allows bruteforcing and breaking BLE session keys, unless the pairing was fully out of band (something that, by the way, I only know one consumer electronics device doing it: the Apple Watch. In the defense of all other consumer electronics, the last time I did iOS development, the APIs for an out of band pairing were not exposed).

It is interesting how, although some of the hacks against this smart card would be possible bruteforcing the connection by intercepting the pairing process, the issue here is simply a total lack of security and authentication of messages and communication. If an adversary got the hands on one of these devices, it is arguably very easy to pull in plaintext the credit card number, expiration date and cc numbers of all cards stored in the device. One does not even need to run Crackle, just standard Linux Bluetooth tools (bluetoothctl and gatttool).

Very interesting read indeed. And yet again, another example of why it is never a good idea to use BLE for connectivity in consumer electronics with high security requirements.

Although for deep security analysis and experiments I do all Bluetooth and BLE things using either an Ubertooth One or my USRP (either B210 or B205mini **) and gr-bluetooth, I always start any experimentation with a basic sniffer.

Until now, my sniffer of choice was the BLE sniffer by Nordic Semiconductor (you can get the dongle for $25 on Adafruit and install the software). Such a simple and small form factor sniffer that runs great on Windows and Linux. I don’t even need to fire up any Linux VM to start poking around.

2269-00

It’s user interface is rather archaic, purely shell-based, but it works just great. And it has a nice added feature that, when listing the devices it detects advertising around you, it automatically adds the device name if it’s advertised in plaintext… which is usually the case.

screen

I was going to set up the sniffer in my laptop today when I noticed that Nordic Semiconductor released a new version of their BLE sniffer. And it is a HUGE update and improvement. The new sniffer is actually integrated as a Wireshark plugin and works great. And allows doing all the work within Wireshark, which is great.

You can follow the instructions on how to install it and set it up here. In a nutshell, you’ll need Python 2.7, pyserial (version 3.4 or higher – to upgrade run pip install pyserial –upgrade), Wireshark 2.4.2 or higher (I like to keep my old installations of Wireshark that I have nicely configured to color-code certain things and have specific columns in specific orders for my work on LTE security, 802.11 security, etc, so I keep several installations of Wireshark on my machine and so did I this time), and Segger J-Link v6.16c (which comes in the sniffer’s compressed file).

By the way, in case you run into the same problem, the instructions are not super clear and it took me some time to realize that one has to copy the contents of “root of the uncompressed folder of the sniffer software\extcap\” to the Wireshark extcap folder (to find it run Wireshark, Help->About->Folders). I had initially copied everything into that folder, d’uh!

I did not manage to get this to work with the nRF51 USB dongle (the one I showed above), but it works great with both the nRF51 and nRF52 development kits.

I have one bit of feedback if anyone from Nordic Semiconductor is reading this. The current way to select the device I want to sniff from, by selecting it from the Device section of the Wireshark plugin, is not very useful. The text is tiny, the partial view of the list is to show and, more importantly, now you guys do not include the advertised device name if it’s in the clear! Hopefully this will be fixed in an upcoming release.

capture_sample.png

Anyhow, happy BLE sniffing folks!

(**) Looking for the USRP mini link I noticed they sell it now with the case and not board and case separately. Hooray! I wonder when they will do the same for the big brother B210.

I was setting up today my new Windows7 laptop. And, as every single Windows laptop I’ve had before, I set up a Linux VM on it. Although on my other laptop I run a paid VMWare Workstation Pro license, in this particular license I am running the free VMWare Workstation 14 Player.

I currently have two VMs set-up, a custom Ubuntu one that I use mostly for development and tests and a Kali-Linux one. If you are interested in radio security, you must install the kali-linux-sdr and kali-linux-wireless packages. Such a convenient way to get all your favorite tools nicely installed on your machine.

By the way, when setting up the Kali image, for some reason, the apt sources were not properly configured and I could not apt-get install kali-linux-sdr and kali-linux-wireless. A quick update of /etc/apt/sources.list fixed the issue. You can get the url to the various package repositories here (note: several of the ones listed do not actually work).

Anyhow, once all my sdr and radio tools are ready to run, I got to the main issue at hand. It is quite well known that running USB devices from within a VM is prone to errors and rather imperfect. Things seem to work fine when, upon plugging my USRP B210, it would be recognized by the driver and connected to the VM.

Running uhd_usrp_probe appeared to work well, as it loaded the firmware onto the USRP, but then it just couldn’t locate the device anymore. For some reason the VM gets lost in translation as, once the firmware is loaded, the USB device essentially changes and the VM loses it. And it took me quite some time to get it to work. I was close to leaving it for another day until I found a solution that worked well on both the Kali and Ubuntu images. Instead of running uhd_usrp_probe or any other application that probes and uses the USRP, the trick is to run first the b2xx_fx3_utils tool. Its path might be different depending on how you installed UHD, but in the Kali image it is in /usr/lib/uhd/utils. After running this tool the firmware is updated on the USRP and, from that moment on, everything works just fine. You will need to do this trick each time that you unplug the USRP and plug it again, as the firmware will need to be updated again.

When I thought I was done, I am actually facing a new challenge. Installing OpenLTE on Kali doesn’t work as cmake cannot find the UHD libraries. Most likely a permissions or weird installation path on Kali for UHD. But this is one that I’ll procrastinate in fixing as I switched to doing all my development and experimentation for my LTE exploits security research with srsLTE.

Ever since becoming a father I’ve had very little time for research, but I have some new LTE protocol exploits in the kitchen being cooked. Once I have enough time to put together results and a talk, you’ll see me on the road to talk about it. I’m aiming for Spring time.

Happy new year everyone!

EDIT: A lot of people has been asking me about this. What this fixes is the USRP itself being used from within a VM. This does not fix the ancient issue of VMWare with USB3 drivers. If you need to run something with the USRP that requires USB3 (e.g. an LTE base station at full 10MHz and ~30Msps), that will be VERY hard to do from within a VM. You are much better off by creating a partition to run native Linux on your laptop for that.

If anyone ever manages to get the USRP over USB3 working from within a VM, please please please let me know!

Earlier this week, Google Scholar highlighted for me a new paper on mobile security. I am familiar with the work of a couple of the authors, so I downloaded it and read the whole thing. It turns out it is, by far, the best overview/compilation of related work in the literature on mobile security research that I have ever seen.

On top of that, the paper analyzes and digests all the literature in a comprehensive way, deriving a methodology to classify attacks by their underlying and root causes, proposed mitigations and solutions, etc.

I strongly recommend folks interested in the area of mobile security to read this paper and as many of the cited works as possible. I’ve given tutorials and workshops on mobile security in the past, and I always include a suggested reading list at the end. From now on, I’ll suggest folks to read the references of this paper, highlighting some of the key ones.

All in all, I strongly recommend downloading this paper. Really good and well organized compilation of published research work on mobile security.

Rupprecht, David, et al. “On Security Research towards Future Mobile Network Generations.” arXiv preprint arXiv:1710.08932(2017).

On a side note, I am slowly progressing in my new research project. Testing a bunch of new attacks, both active and passive, with a modified version of srsLTE. Pretty awesome tool.

Ever since back in 2010 I started investigating what would happen if a radio adversary jammed specific LTE signaling channels – as opposed to barrage jamming of the entire LTE signal -, I have been very interested in what I referred as to Smart Jamming back in 2013 and again in 2014.

smart_jammingA team in Virginia Tech has been one of the main players in the research field of smart jamming, more commonly known as Protocol-Aware Jamming. Starting with their 2013 paper “Vulnerability of LTE to Hostile Interference“, this team has published a bunch of interesting results in this area, including a paper in which I collaborated with them.

The same team just released a pre-print version of their Milcom paper in which they actually implement smart jamming attacks against downlink signaling channels using off-the-shelf software defined radios and open-source software. It makes me happy every time there is a new excellent work in LTE security which implements and tests exploits, attacks and solutions using open-source software. Over a year ago I wrote a short article on how I anticipated a spike in excellent LTE security research work now that the open-source implementations of LTE have reached a high level of maturity.

In the case of the Virginia Tech paper, they implement their protocol-aware jamming use cases on top of the srsLTE tool, which has always been one of the most complete LTE open-source implementation and might currently be the best one. It is also, to the date, the only tool that provides a full implementation of the UE LTE stack.

Read the paper on smart jamming implementation on SDRs running srsLTE here:

R. Rao, S. Ha, V. Marojevic, J.H. Reed, “LTE PHY Layer Vulnerability Analysis and Testing Using Open-Source SDR Tools”, IEEE MILCOM 2017, 23-25 Oct. 2017.

Happy Saturday!

ps. Dembele better be good. Let’s try to get Coutinho now. Though I feel terrible we are just adding more fuel to the fire of the over-inflated and out of control European soccer transfer market…

About me:

Born in Barcelona, moved to Los Angeles at age 24, ended in NYC, where I enjoy life, tweet about music and work as a geek in security for wireless networks.
All the opinions expressed in this blog are my own and are not related to my employer.
About me: http://rogerpiquerasjover.net/

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