CANflict: Exploiting Peripheral Conflicts for Data-Link Layer Attacks on Automotive Networks

Current research in the automotive domain has proven the limitations of the CAN protocol from a security standpoint. Application-layer attacks, which involve the creation of malicious packets, are deemed feasible from remote but can be easily detected by modern IDS. On the other hand, more recent link-layer attacks are stealthier and possibly more disruptive but require physical access to the bus. In this paper, we present CANflict, a software-only approach that allows reliable manipulation of the CAN bus at the data link layer from an unmodified microcontroller, overcoming the limitations of state-of-the-art works. We demonstrate that it is possible to deploy stealthy CAN link-layer attacks from a remotely compromised ECU, targeting another ECU on the same CAN network. To do this, we exploit the presence of pin conflicts between microcontroller peripherals to craft polyglot frames, which allows an attacker to control the CAN traffic at the bit level and bypass the protocol's rules. We experimentally demonstrate the effectiveness of our approach on high-, mid-, and low-end microcontrollers, and we provide the ground for future research by releasing an extensible tool that can be used to implement our approach on different platforms and to build CAN countermeasures at the data link layer.Comment: To appear in CCS'2

Reducing the Attack Surface of Dynamic Binary Instrumentation Frameworks

Malicious applications pose as one of the most relevant issues in today’s technology scenario, being considered the root of many Internet security threats. In part, this owes the ability of malware developers to promptly respond to the emergence of new security solutions by developing artifacts to detect and avoid them. In this work, we present three countermeasures to mitigate recent mechanisms used by malware to detect analysis environments. Among these techniques, this work focuses on those that enable a malware to detect dynamic binary instrumentation frameworks, thus increasing their attack surface. To ensure the effectiveness of the proposed countermeasures, proofs of concept were developed and tested in a controlled environment with a set of anti-instrumentation techniques. Finally, we evaluated the performance impact of using such countermeasures

There’s a Hole in that Bucket! A Large-scale Analysis of Misconfigured S3 Buckets

Cloud storage services are an efficient solution for a variety of use cases, allowing even non-skilled users to benefit from fast, reliable and easy-to-use storage. However, using public cloud services for storage comes with security and privacy concerns. In fact, manag- ing access control at scale is often particularly hard, as the size and complexity rapidly increases, especially when the role of access policies is underestimated, resulting in dangerous misconfigurations. In this paper, we investigate the usage of Amazon S3, one of the most popular cloud storage services, focusing on automatically analyzing and discovering misconfigurations that affect security and privacy. We developed a tool that automatically performs security checks of S3 buckets, without storing nor exposing any sensitive data. This tool is intended for developers, end-users, enterprises, and any other organization that makes extensive use of S3 buckets. We validate our tool by performing the first comprehensive, large- scale analysis of 240,461 buckets, obtaining insights on the most common mistakes in access control policies. The most concerning one is certainly the (unwanted) exposure of storage buckets: These can easily leak sensitive data, such as private keys, credentials and database dumps, or allow attackers to tamper with their resources. To raise awareness on the risks and help users to secure their storage services, we show how attackers could exploit unsecured S3 buckets to deface or deliver malicious content through websites that relies on S3 buckets. In fact, we identify 191 vulnerable websites. Finally, we propose a browser extension that prevents loading re- sources hosted in unsecured buckets, intended either for end-users, as a mitigation against vulnerable websites, and for developers and software testers, as a way to check for misconfigurations