Biblio

Autonomous systems (ASes) on the Internet increasingly rely on Internet Exchange Points (IXPs) for peering. A single IXP may interconnect several 100s or 1000s of participants (ASes) all of which might peer with each other through BGP sessions. IXPs have addressed this scaling challenge through the use of route servers. However, route servers require participants to trust the IXP and reveal their policies, a drastic change from the accepted norm where all policies are kept private. In this paper we look at techniques to build route servers which provide the same functionality as existing route servers without requiring participants to reveal their policies thus preserving the status quo and enabling wider adoption of IXPs. Prior work has looked at secure multiparty computation (SMPC) as a means of implementing such route servers however this affects performance and reduces policy flexibility. In this paper we take a different tack and build on trusted execution environments (TEEs) such as Intel SGX to keep policies private and flexible. We present results from an initial route server implementation that runs under Intel SGX and show that our approach has 20x better performance than SMPC based approaches. Furthermore, we demonstrate that the additional privacy provided by our approach comes at minimal cost and our implementation is at worse 2.1x slower than a current route server implementation (and in some situations up to 2x faster).

In this paper, we present two web-based attacks against local IoT devices that any malicious web page or third-party script can perform, even when the devices are behind NATs. In our attack scenario, a victim visits the attacker's website, which contains a malicious script that communicates with IoT devices on the local network that have open HTTP servers. We show how the malicious script can circumvent the same-origin policy by exploiting error messages on the HTML5 MediaError interface or by carrying out DNS rebinding attacks. We demonstrate that the attacker can gather sensitive information from the devices (e.g., unique device identifiers and precise geolocation), track and profile the owners to serve ads, or control the devices by playing arbitrary videos and rebooting. We propose potential countermeasures to our attacks that users, browsers, DNS providers, and IoT vendors can implement.

Software Defined Internet Exchange Points (SDXes) increase the flexibility of interdomain traffic delivery on the Internet. Yet, an SDX inherently requires multiple participants to have access to a single, shared physical switch, which creates the need for an authorization mechanism to mediate this access. In this paper, we introduce a logic and mechanism called FLANC (A Formal Logic for Authorizing Network Control), which authorizes each participant to control forwarding actions on a shared switch and also allows participants to delegate forwarding actions to other participants at the switch (e.g., a trusted third party). FLANC extends "says" and "speaks for" logic that have been previously designed for operating system objects to handle expressions involving network traffic flows. We describe FLANC, explain how participants can use it to express authorization policies for realistic interdomain routing settings, and demonstrate that it is efficient enough to operate in operational settings.

Modern websites use multiple authentication cookies to allow visitors to the site different levels of access. The complexity of modern web applications can make it difficult for a web application programmer to ensure that the use of authentication cookies does not introduce vulnerabilities. Even when a programmer has access to all of the source code, this analysis can be challenging; the problem becomes even more vexing when web programmers cobble together off-the-shelf libraries to implement authentication. We have assembled a checklist for modern web programmers to verify that the cookie based authentication mechanism is securely implemented. Then, we developed a tool, Newton, to help a web application programmer to identify authentication cookies for specific parts of the website and to verify that they are securely implemented according to the checklist. We used Newton to analyze 149 sites, including the Alexa top-200 and many other popular sites across a range of categories including search, shopping, and finance. We found that 113 of them–-including high-profile sites such as Yahoo, Amazon, and Fidelity–-were vulnerable to hijacking attacks. Many websites have already acknowledged and fixed the vulnerabilities that we found using Newton and reported to them.