October 19, 2017

Mitigating the Increasing Risks of an Insecure Internet of Things

The emergence and proliferation of Internet of Things (IoT) devices on industrial, enterprise, and home networks brings with it unprecedented risk. The potential magnitude of this risk was made concrete in October 2016, when insecure Internet-connected cameras launched a distributed denial of service (DDoS) attack on Dyn, a provider of DNS service for many large online service providers (e.g., Twitter, Reddit). Although this incident caused large-scale disruption, it is noteworthy that the attack involved only a few hundred thousand endpoints and a traffic rate of about 1.2 terabits per second. With predictions of upwards of a billion IoT devices within the next five to ten years, the risk of similar, yet much larger attacks, is imminent.

The Growing Risks of Insecure IoT Devices

One of the biggest contributors to the risk of future attack is the fact that many IoT devices have long-standing, widely known software vulnerabilities that make them vulnerable to exploit and control by remote attackers. Worse yet, the vendors of these IoT devices often have provenance in the hardware industry, but they may lack expertise or resources in software development and systems security. As a result, IoT device manufacturers may ship devices that are extremely difficult, if not practically impossible, to secure. The large number of insecure IoT devices connected to the Internet poses unprecedented risks to consumer privacy, as well as threats to the underlying physical infrastructure and the global Internet at large:

  • Data privacy risks. Internet-connected devices increasingly collect data about the physical world, including information about the functioning of infrastructure such as the power grid and transportation systems, as well as personal or private data on individual consumers. At present, many IoT devices either do not encrypt their communications or use a form of encrypted transport that is vulnerable to attack. Many of these devices also store the data they collect in cloud-hosted services, which may be the target of data breaches or other attack.
  • Risks to availability of critical infrastructure and the Internet at large. As the Mirai botnet attack of October 2016 demonstrated, Internet services often share underlying dependencies on the underlying infrastructure: crippling many websites offline did not require direct attacks on these services, but rather a targeted attack on the underlying infrastructure on which many of these services depend (i.e., the Domain Name System). More broadly, one might expect future attacks that target not just the Internet infrastructure but also physical infrastructure that is increasingly Internet- connected (e.g., power and water systems). The dependencies that are inherent in the current Internet architecture create immediate threats to resilience.

    The large magnitude and broad scope of these risks implore us to seek solutions that will improve infrastructure resilience in the face of Internet-connected devices that are extremely difficult to secure. A central question in this problem area concerns the responsibility that each stakeholder in this ecosystem should bear, and the respective roles of technology and regulation (whether via industry self-regulation or otherwise) in securing both the Internet and associated physical infrastructure against these increased risks.

Risk Mitigation and Management

One possible lever for either government or self-regulation is the IoT device manufacturers. One possibility, for example, might be a device certification program for manufacturers that could attest to adherence to best common practice for device and software security. A well-known (and oft-used) analogy is the UL certification process for electrical devices and appliances.

Despite its conceptual appeal, however, a certification approach poses several practical challenges. One challenge is outlining and prescribing best common practices in the first place, particularly due to the rate at which technology (and attacks) progress. Any specific set of prescriptions runs the risk of falling out of date as technology advances; similarly, certification can readily devolve into a checklist of attributes that vendors satisfy, without necessarily adhering to the process by which these devices are secured over time. As daunting as challenges of specifying a certification program may seem, enforcing adherence to a certification program may prove even more challenging. Specifically, consumers may not appreciate the value of certification, particularly if meeting the requirements of certification increases the cost of a device. This concern may be particularly acute for consumer IoT, where consumers may not bear the direct costs of connecting insecure devices to their home networks.

The consumer is another stakeholder who could be incentivized to improve the security of the devices that they connect to their networks (in addition to more effectively securing the networks to which they connect these devices). As the entity who purchases and ultimately connects IoT devices to the network, the consumer appears well-situated to ensure the security of the IoT devices on their respective networks. Unfortunately, the picture is a bit more nuanced. First, consumers typically lack either the aptitude or interest (or both!) to secure either their own networks or the devices that they connect to them. Home broadband Internet access users have generally proved to be poor at applying software updates in a timely fashion, for example, and have been equally delinquent in securing their home networks. Even skilled network administrators regularly face network misconfigurations, attacks, and data breaches. Second, in many cases, users may lack the incentives to ensure that their devices are secure. In the case of the Mirai botnet, for example, consumers did not directly face the brunt of the attack; rather, the ultimate victims of the attack were DNS service providers and, indirectly, online service providers such as Twitter. To the first order, consumers suffered little direct consequence as a result of insecure devices on their networks.

Consumers’ misaligned incentives suggest several possible courses of action. One approach might involve placing some responsibility or liability on consumers for the devices that they connect to the network, in the same way that a citizen might be fined for other transgressions that have externalities (e.g., fines for noise or environmental pollution). Alternatively, Internet service providers (or another entity) might offer users a credit for purchasing and connecting only devices that it pass certification; another variation of this approach might require users to purchase ”Internet insurance” from their Internet service providers that could help offset the cost of future attacks. Consumers might receive credits or lower premiums based on the risk associated with their behavior (i.e., their software update practices, results from security audits of devices that they connect to the network).

A third stakeholder to consider is the Internet service provider (ISP), who provides Internet connectivity to the consumer. The ISP has considerable incentives to ensure that the devices that its customer connects to the network are secure: insecure devices increase the presence of attack traffic and may ultimately degrade Internet service or performance for the rest of the ISPs’ customers. From a technical perspective, the ISP is also in a uniquely effective position to detect and squelch attack traffic coming from IoT devices. Yet, relying on the ISP alone to protect the network against insecure IoT devices is fraught with non-technical complications. Specifically, while the ISP could technically defend against an attack by disconnecting or firewalling consumer devices that are launching attacks, such an approach will certainly result in increased complaints and technical support calls from customers, who connect devices to the network and simply expect them to work. Second, many of the technical capabilities that an ISP might have at its disposal (e.g., the ability to identify attack traffic coming from a specific device) introduce serious privacy concerns. For example, being able to alert a customer to (say) a compromised baby monitor requires the ISP to know (and document) that a consumer has such a device in the first place.

Ultimately, managing the increased risks associated with insecure IoT devices may require action from all three stakeholders. Some of the salient questions will concern how the risks can be best balanced against the higher operational costs that will be associated with improving security, as well as who will ultimately bear these responsibilities and costs.

Improving Infrastructure Resilience

In addition to improving defenses against the insecure devices themselves, it is also critical to determine how to better build resilience into the underlying Internet infrastructure to cope with these attacks. If one views the occasional IoT-based attack inevitable to some degree, one major concern is ensuring that the Internet Infrastructure (and the associated cyberphysical infrastructure) remains both secure and available in the face of attack. In the case of the Mirai attack on Dyn, for example, the severity of the attack was exacerbated by the fact that many online services depended on the infrastructure that was attacked. Computer scientists and Internet engineers should be thinking about technologies that can both potentially decouple these underlying dependencies and ensure that the infrastructure itself remains secure even in the event that regulatory or legal levers fail to prevent every attack. One possibility that we are exploring, for example, is the role that an automated home network firewall could play in (1) help- ing users keep better inventory of connected IoT devices; (2) providing users both visibility into and control over the traffic flows that these devices send.

Summary

Improving the resilience of the Internet and cyberphysical infrastructure in the face of insecure IoT devices will require a combination of technical and regulatory mechanisms. Engineers and regulators will need to work together to improve security and privacy of the Internet of Things. Engineers must continue to advance the state of the art in technologies ranging from lightweight encryption to statistical network anomaly detection to help reduce risk; similarly, engineers must design the network to improve resilience in the face of the increased risk of attack. On the other hand, realizing these advances in deployment will require the appropriate alignment of incentives, so that the parties that introduce risks are more aligned with those who bear the costs of the resulting attacks.