Weekend Reads 110818

KrebsOnSecurity recently had a chance to interview members of the REACT Task Force, a team of law enforcement officers and prosecutors based in Santa Clara, Calif. that has been tracking down individuals engaged in unauthorized “SIM swaps” — a complex form of mobile phone fraud that is often used to steal large amounts of cryptocurrencies and other items of value from victims. Snippets from that fascinating conversation are recounted below, and punctuated by accounts from a recent victim who lost more than $100,000 after his mobile phone number was hijacked. @Krebs on Security

PortSmash, as the new attack is being called, exploits a largely overlooked side-channel in Intel’s hyperthreading technology. A proprietary implementation of simultaneous multithreading, hyperthreading reduces the amount of time needed to carry out parallel computing tasks, in which large numbers of calculations or executions are carried out simultaneously. The performance boost is the result of two logical processor cores sharing the hardware of a single physical processor. The added logical cores make it easier to divide large tasks into smaller ones that can be completed more quickly. —Dan Goodin @ARS Technica

Security researchers have unveiled details of two critical vulnerabilities in Bluetooth Low Energy (BLE) chips embedded in millions of access points and networking devices used by enterprises around the world. Dubbed BleedingBit, the set of two vulnerabilities could allow remote attackers to execute arbitrary code and take full control of vulnerable devices without authentication, including medical devices such as insulin pumps and pacemakers, as well as point-of-sales and IoT devices. —Swati Khandelwal @The Hacker News

Crooks who hack online merchants to steal payment card data are constantly coming up with crafty ways to hide their malicious code on Web sites. In Internet ages past, this often meant obfuscating it as giant blobs of gibberish text that was obvious even to the untrained eye. These days, a compromised e-commerce site is more likely to be seeded with a tiny snippet of code that invokes a hostile domain which appears harmless or that is virtually indistinguishable from the hacked site’s own domain. @Krebs on Security

Over the last several years, Facebook has gone from facilitating the free flow of information to inhibiting it through incremental censorship and account purges. What began with the ban of Alex Jones last summer has since escalated to include the expulsion of hundreds of additional pages, each political in nature. And as more people become wary of the social media platform’s motives, one thing is absolutely certain: we need more market competition in the realm of social media. —Brittany Hunter @Interllectual Takeout

Tim Berners-Lee, a London-born computer scientist who invented the Web in 1989, said he was disappointed with the current state of the internet, following scandals over the abuse of personal data and the use of social media to spread hate. “What naturally happens is you end up with one company dominating the field so through history there is no alternative to really coming in and breaking things up,” Berners-Lee, 63, said in an interview. “There is a danger of concentration.” —Guy Faulconbridge, Paul Sandle @Reuters

It’s been three years since Australia adopted a national copyright blocking system, despite widespread public outcry over the abusive, far-reaching potential of the system, and the warnings that it would not achieve its stated goal of preventing copyright infringement. Three years later, the experts who warned that censorship wouldn’t drive people to licensed services have been vindicated. According to the giant media companies who drove the copyright debate in 2015, the national censorship system has not convinced Australians to pay up. —Cory Doctorow @EFF

Thiel said Silicon Valley has fallen victim to groupthink, citing its politically insular atmosphere for his moving away to Los Angeles. “There’s a sense that the network effects that made Silicon Valley good have gone haywire,” he said, according to CNBC. “It’s not the wisdom of crowds, it’s the madness of crowds.” @Market Watch

Google Chrome is the most popular browser in the world. Chrome routinely leads the pack in features for security and usability, most recently helping to drive the adoption of HTTPS. But when it comes to privacy, specifically protecting users from tracking, most of its rivals leave it in the dust. —Bennett Cyphers and Mitch Stoltz @EFF

Network Troubleshooting Webinar on Safari Books

I just redid my slides for the network troubleshooting seminar I teach on Safari Books from time to time. This new set of slides should make for a better webinar. The outline now covers—

Segment 1: Foundations
Length: 50 minutes

  • MTTR, MTBM, MTBM
  • Resiliency in terms of troubleshooting
  • Positive feedback loops
  • Automated processes and fragility
  • The troubleshooting process
  • Avoiding the narrows
  • Using models to dive deeper
  • Using abstraction to counter the combinatorial explosion
  • When abstractions leak
  • What, how, and why models

10 Minute Break

Segment 2: Process
Length: 50 minutes

  • The theory of half split, as seen from search trees
  • Putting it together: a simple troubleshooting loop and the half-split
  • Using manipulability theory to prove it
  • Observations on observations

10 Minute Break

Segment 3: Examples
Length: 50 minutes

  • The EIGRP case
  • The BGP case
  • IS-IS and BFD

10 minute final Question and Answer Period

You can register here. Note the name of the seminar is changing, so the URL might change, as well.

BGP Hijacks: Two more papers consider the problem

The security of the global Default Free Zone DFZ) has been a topic of much debate and concern for the last twenty years (or more). Two recent papers have brought this issue to the surface once again—it is worth looking at what these two papers add to the mix of what is known, and what solutions might be available. The first of these—

Demchak, Chris, and Yuval Shavitt. 2018. “China’s Maxim – Leave No Access Point Unexploited: The Hidden Story of China Telecom’s BGP Hijacking.” Military Cyber Affairs 3 (1). https://doi.org/10.5038/2378-0789.3.1.1050.

—traces the impact of Chinese “state actor” effects on BGP routing in recent years.

cross posted to CircleID

Whether these are actual attacks, or mistakes from human error for various reasons generally cannot be known, but the potential, at least, for serious damage to companies and institutions relying on the DFZ is hard to overestimate. This paper lays out the basic problem, and the works through a number of BGP hijacks in recent years, showing how they misdirected traffic in ways that could have facilitated attacks, whether by mistake or intentionally. For instance, quoting from the paper—

  • Starting from February 2016 and for about 6 months, routes from Canada to Korean government sites were hijacked by China Telecom and routed through China.
  • On October 2016, traffic from several locations in the USA to a large Anglo-American bank
  • headquarters in Milan, Italy was hijacked by China Telecom to China.
  • Traffic from Sweden and Norway to the Japanese network of a large American news organization was hijacked to China for about 6 weeks in April/May 2017.

What impact could such a traffic redirection have? If you can control the path of traffic while a TLS or SSL session is being set up, you can place your server in the middle as an observer. This can, in many situations, be avoided if DNSSEC is deployed to ensure the certificates used in setting up the TLS session is valid, but DNSSEC is not widely deployed, either. Another option is to simply gather encrypted traffic and either attempt to break the key, or use data analytics to understand what the flow is doing (a side channel attack).

What can be done about these kinds of problems? The “simplest”—and most naïve—answer is “let’s just secure BGP.” There are many, many problems with this solution. Some of them are highlighted in the second paper under review—

Bonaventure, Olivier. n.d. “A Survey among Network Operators on BGP Prefix Hijacking – Computer Communication Review.” Accessed November 3, 2018. https://ccronline.sigcomm.org/2018/ccr-january-2018/a-survey-among-network-operators-on-bgp-prefix-hijacking/.

—which illustrates the objections providers have to the many forms of BGP security that have been proposed to this point. The first is, of course, that it is expensive. The ROI of the systems proposed thus far are very low; the cost is high, and the benefit to the individual provider is rather low. There is both a race to perfection problem here, as well as a tragedy of the commons problem. The race to perfection problem is this: we will not design, nor push for the deployment of, any system which does not “solve the problem entirely.” This has been the mantra behind BGPSEC, for instance. But not only is BGPSEC expensive—I would say to the point of being impossible to deploy—it is also not perfect.

The second problem in the ROI space is the tragedy of the commons. I cannot do much to prevent other people from misusing my routes. All I can really do is stop myself and my neighbors from misusing other people’s routes. What incentive do I have to try to make the routing in my neighborhood better? The hope that everyone else will do the same. Thus, the only way to maintain the commons of the DFZ is for everyone to work together for the common good. This is difficult. Worse than herding cats.

A second point—not well understood in the security world—is this: a core point of DFZ routing is that when you hand your reachability information to someone else, you lose control over that reachability information. There have been a number of proposals to “solve” this problem, but it is a basic fact that if you cannot control the path traffic takes through your network, then you have no control over the profitability of your network. This tension can be seen in the results of the survey above. People want security, but they do not want to release the information needed to make security happen. Both realities are perfectly rational!

Part of the problem with the “more strict,” and hence (considered) “more perfect” security mechanisms proposed is simply this: they are not quiet enough. They expose far too much information. Even systems designed to prevent information leakage ultimately leak too much.

So… what do real solutions on the ground look like?

One option is for everyone to encrypt all traffic, all the time. This is a point of debate, however, as it also damages the ability of providers to optimize their networks. One point where the plumbing allegory for networking breaks down is this: all bits of water are the same. Not all bits on the wire are the same.

Another option is to rely less on the DFZ. We already seem to be heading in this direction, if Geoff Huston and other researchers are right. Is this a good thing, or a bad one? It is hard to tell from this angle, but a lot of people think it is a bad thing.

Perhaps we should revisit some of the proposed BGP security solutions, reshaping some of them into something that is more realistic and deployable? Perhaps—but the community is going to let go of the “but it’s not perfect” line of thinking, and start developing some practical, deployable solutions that don’t leak so much information.

Finally, there is a solution Leslie Daigle and I have been tilting at for a couple of years now. Finding a way to build a set of open source tools that will allow any operator or provider to quickly and cheaply build an internal system to check the routing information available in their neighborhood on the ‘net, and mix local policy with that information to do some bare bones work to make their neighborhood a little cleaner. This is a lot harder than “just build some software” for various reasons; the work is often difficult—as Leslie says, it is largely a matter of herding cats, rather than inventing new things.