Despite the widespread deployment of 5G technologies, there exists a critical gap in security testing for 5G Standalone (SA) devices. Existing methods, largely manual and labor-intensive, are ill-equipped to fully uncover the state of security in the implementations of 5G SA protocols and standards on devices, severely limiting the ability to conduct comprehensive evaluations. To address this issue, in this work, we introduce a novel, open-source framework that automates the security testing process for 5G SA devices. By leveraging enhanced functionalities of 5G SA core and Radio Access Network (RAN) software, our framework offers a streamlined approach to generating, executing, and evaluating test cases, specifically focusing on the Non-Access Stratum layer. Our application of this framework across multiple 5G SA devices provides in-depth security insights, significantly improving testing efficiency and breadth.

FMCW radars are integral to automotive driving for robust and weather-resistant sensing of surrounding objects. However, these radars are vulnerable to spoofing attacks that can cause sensor malfunction and potentially lead to accidents. Previous attempts at spoofing FMCW radars using an attacker device have not been very effective due to the need for synchronization between the attacker and the victim. We present a novel spoofing mechanism called mmSpoof that does not require synchronization and is resilient to various security features and countermeasures of the victim radar. Our spoofing mechanism uses a "reflect array" based attacker device that reflects the radar signal with appropriate modulation to spoof the victim’s radar. We provide insights and mechanisms to flexibly spoof any distance and velocity on the victim’s radar using a unique frequency shift at the mmSpoof’s reflect array. We design a novel algorithm to estimate this frequency shift without assuming prior information about the victim’s radar. We show the effectiveness of our spoofing using a compact and mobile setup with commercial-off-the-shelf components in realistic automotive driving scenarios with commercial radars.

Security flaws and vulnerabilities in cellular networks lead to severe security threats given the data-plane services that are involved, from calls to messaging and Internet access. While the 5G Standalone (SA) system is currently being deployed worldwide, practical security testing of User Equipment (UE) has only been conducted and reported publicly for 4G/LTE and earlier network generations. In this paper, we develop and present the first open-source based security testing framework for 5G SA User Equipment. To that end, we modify the functionality of open-source suites (Open5GS and srsRAN) and develop a broad set of test cases for the 5G NAS and RRC layers. We apply our testing framework in a proof-of-concept manner to 5G SA mobile phones and provide detailed insights from our experiments. While being a framework in development, the results of our experiments presented in this paper can assist other researchers in the field and have the potential to improve 5G SA security.

In this work, we demonstrate the possibility of spoofing a GNSS receiver to arbitrary locations without modifying the navigation messages. Due to increasing spoofing threats, Galileo and GPS are evaluating broadcast authentication techniques to validate the integrity of navigation messages. Prior work required an adversary to record the GNSS signals at the intended spoofed location and relay them to the victim receiver. Our attack demonstrates the ability of an adversary to receive signals close to the victim receiver and in real-time generate spoofing signals for an arbitrary location without modifying the navigation message contents. We exploit the essential common reception and transmission time method used to estimate pseudorange in GNSS receivers, thereby potentially rendering any cryptographic authentication useless. We build a proof-of-concept real-time spoofer capable of receiving authenticated GNSS signals and generating spoofing signals for any arbitrary location and motion without requiring any high-speed communication networks or modifying the message contents. Our evaluations show that it is possible to spoof a victim receiver to locations as far as 4000~km away from the actual location and with any dynamic motion path. This work further highlights the fundamental limitations in securing a broadcast signaling-based localization system even if all communications are cryptographically protected.

Bluetooth-based item trackers have sparked apprehension over their potential misuse in harmful stalking and privacy violations. In response, manufacturers have implemented safety alerts to notify victims of extended tracking by unknown item trackers. In this study, we specifically investigate the anti-stalking mechanism of Apple's AirTag. We identify and analyze potential triggers of safety alerts that have not been examined in previous research, such as the local time, the victim's device model, AirTag's battery life, and the distance between the AirTag and the victim's device. Furthermore, we demonstrate a novel possibility of developing a stealthy cloned AirTag capable of tracking victims directly on the Find My app while circumventing safety alerts on the victim’s device. Our experiments demonstrate that, despite regular updates to the public key and MAC address, our cloned AirTag can provide real-time location updates even with a four months old key, thereby highlighting the challenges in designing a robust anti-stalking framework. Furthermore, we propose practical solutions to mitigate stalking risks from cloned AirTags and enhance the existing anti-stalking safeguards for AirTags. These suggestions seek to provide a foundation for similar Bluetooth-based item trackers to improve their anti-stalking protections while ensuring optimal tracking efficiency. We conducted rigorous experiments to validate our findings, ensuring their accuracy and reliability. Our evaluation highlights that safety alerts take over 8 hours to appear during the day and are more prompt during the night, particularly after 11 pm.

Aviation datalink applications such as controller-pilot datalink communications (CPDLC) and automatic dependent surveillance-contract (ADS-C) were designed to supplement existing communication systems to accommodate increasing air traffic. These applications are typically used to provide departure clearance, en-route services such as altitude and flight plan changes, air traffic surveillance and reporting, and radio frequency assignments. Unlike most attacks proposed so far where the attacker influences decision-making through manipulated instruments, attacks on aviation datalink provide adversaries with a new attack vector to influence the flight crew’s decision-making through direct instructions. In this work, we perform a security analysis of these applications and outline the requirements for executing a successful attack. Specifically, we propose a coordinated multi-aircraft attack and show how an adversary capable of spoofing datalink messages and reactive jamming can influence the flight crew’s decision-making. Through geospatial analysis of historical flight data, we identify 48 vulnerable regions where an attacker has a 90% chance of encountering favorable conditions for coordinated multi-aircraft attacks. Next, we implement a reactive jammer that ensures stealthy attack execution by targeting messages from a specific aircraft with a reaction time of 1.48 ms and 98.85% jamming success. Even though by themselves these attacks have a lower probability of endangering the safety of the aircraft, the threat is magnified when combined with attacks on other avionics. Finally, we discuss the possibility of executing integrated attacks on aircraft system as a whole emphasizing the importance of securing individual components in the aviation ecosystem.

With the introduction of WPA3 and Wi-Fi 6, an increased usage of Wi-Fi Management Frame Protection (MFP) is expected. Wi-Fi MFP, defined in IEEE 802.11w, protects robust management frames by providing data confidentiality, integrity, origin authenticity, and replay protection. One of its key goals is to prevent deauthentication attacks in which an adversary forcibly disconnects a client from the network. In this paper, we inspect the standard and its implementations for their robustness and protection against deauthentication attacks. In our standard analysis, we inspect the rules for processing robust management frames on their completeness, consistency, and security, leading to the discovery of unspecified cases, contradictory rules, and revealed insecure rules that lead to new denial-of-service vulnerabilities. We then inspect implementations and identify vulnerabilities in clients and access points running on the latest versions of the Linux kernel, hostap, IWD, Apple (i.e., macOS, iOS, iPadOS), Windows, and Android. Altogether, these vulnerabilities allow an adversary to disconnect any client from personal and enterprise networks despite the usage of MFP. Our work highlights that management frame protection is insufficient to prevent deauthentication attacks, and therefore more care is needed to mitigate attacks of this kind. In order to address the identified shortcomings, we worked with industry partners to propose updates to the IEEE 802.11 standard.

Abstract With the standardization of Wi-Fi Fine Timing Measurement (Wi-Fi FTM; IEEE 802.11mc), the IEEE introduced indoor positioning for Wi-Fi networks. To date, Wi-Fi FTM is the most widely supported Wi-Fi distance measurement and positioning system. In this paper, we perform the first privacy analysis of Wi-Fi FTM and evaluate devices from a wide variety of vendors. We find the protocol inherently leaks location-sensitive information. Most notably, we present techniques that allow any client to be localized and tracked by a solely passive adversary. We identify flaws inWi-Fi FTM MAC address randomization and present techniques to fingerprint stations with firmware-specific granularity further leaking client identity. We address these shortcomings and present a privacy-preserving passive positioning system that leverages existing Wi-Fi FTM infrastructure and requires no hardware changes. Due to the absence of any client-side transmission, our design hides the very existence of a client and as a side-effect improves overall scalability without compromising on accuracy. Finally, we present privacy-enhancing recommendations for the current and next-generation protocols such as Wi-Fi Next Generation Positioning (Wi-Fi NGP; IEEE 802.11az).

Motivated by the recent push towards adopting new standards and the discovery of numerous vulnerabilities in both new and old protocols, this paper analyzes the security of Wi-Fi networks. Our analysis is based on publicly available datasets and our own survey covering 250,137 networks across four countries in three continents. We present several key insights, including the continued use of outdated security configurations and vulnerable protocols, the adoption rates of modern protocols, the increasing presence of mesh networks as part of smart city infrastructure, and the vast differences depending on the surveyed geographic region and frequency spectrum. Additionally, we identify and improve upon shortcomings in previous surveys, and recommend best practices for future surveying. In summary, our work provides a more fine-grained understanding on Wi-Fi network security in the real-world. Finally, we publish our tools used for extracting security statistics, and make all anonymized datasets available to other researchers.

Today, an increasing number of applications rely on location and proximity information to deliver services. With the introduction of Wi-Fi Fine Timing Measurement (FTM) in the IEEE 802.11-2016 standard, Wi-Fi derived location and proximity information will play a key role in many safety- and security-critical applications. For example, Wi-Fi FTM is adopted in Wi-Fi Aware where it enables geo-fencing and mobile identification. In this paper, we perform the first security analysis of Wi-Fi FTM and analyze its security guarantees across the logical and physical layers. We find various weaknesses that enable an attacker to introduce distance reductions and enlargements to any arbitrary attacker-chosen value, requiring commodity hardware only. We perform an evaluation using commercial access points, smartphones, and off-the-shelf Wi-Fi cards, and show that an attacker can manipulate distances with meter-level precision. Furthermore, we highlight the distance manipulation attacks which are independent of any higher-layer cryptographic protection, exposing fundamental limitations to achieving secure distance measurements in the current standard. Finally, we present security recommendations for the design and implementation of Wi-Fi FTM and next-generation positioning protocols.

Over the years, numerous weaknesses have been identified in the IEEE 802.11 standard and its implementations. In order to present a proof-of-concept or demonstrate their impact in practice, researchers are often required to implement entire procedures or complex features from scratch (e.g., injecting encrypted frames with customized header flags). In this paper, we present a framework that allows researchers to more easily test and fuzz any device (i.e., access points and clients). This framework enables one to, for example, test hypothesis on new weaknesses, implement proof-of-concepts, create testing suites, and automate experiments. Our framework is implemented on top of the hostap user space daemon, and includes a language in which complex test cases can be defined (e.g., instructions to inject a sequence of user-modified frames into the network). Notably, a test case can make use of the hostap control interface, providing access to built-in features (e.g., authentication procedures, retrieval of encryption keys) and allows users to create customized hostap extensions.

We measure the usage of cipher suites in protected Wi-Fi networks, and do this for several distinct geographic areas. Surprisingly, we found that 44.81% of protected networks still support the old WPA-TKIP cipher. Motivated by this, we systematically analyze the security of several implementations of WPA-TKIP, and present novel side-channel attacks against them. The presented attacks bypass existing countermeasures and recover the Michael message authentication key in 1 to 4 minutes. Using this key, an adversary can then decrypt and inject network traffic. In contrast, previous attacks needed 7 to 8 minutes. These results stress the urgent need to stop using WPA-TKIP.

Location information is critical to a wide variety of navigation and tracking applications. GPS, today's de-facto outdoor localization system has been shown to be vulnerable to signal spoofing attacks. Inertial Navigation Systems (INS) are emerging as a popular complementary system, especially in road transportation systems as they enable improved navigation and tracking as well as offer resilience to wireless signals spoofing and jamming attacks. In this paper, we evaluate the security guarantees of INS-aided GPS tracking and navigation for road transportation systems. We consider an adversary required to travel from a source location to a destination and monitored by an INS-aided GPS system. The goal of the adversary is to travel to alternate locations without being detected. We develop and evaluate algorithms that achieve this goal, providing the adversary significant latitude. Our algorithms build a graph model for a given road network and enable us to derive potential destinations an attacker can reach without raising alarms even with the INS-aided GPS tracking and navigation system. The algorithms render the gyroscope and accelerometer sensors useless as they generate road trajectories indistinguishable from plausible paths (both in terms of turn angles and roads curvature). We also design, build and demonstrate that the magnetometer can be actively spoofed using a combination of carefully controlled coils. To experimentally demonstrate and evaluate the feasibility of the attack in real-world, we implement a first real-time integrated GPS/INS spoofer that accounts for traffic fluidity, congestion, lights, and dynamically generates corresponding spoofing signals. Furthermore, we evaluate our attack on ten different cities using driving traces and publicly available city plans. Our evaluations show that it is possible for an attacker to reach destinations that are as far as 30 km away from the actual destination without being detected. We also show that it is possible for the adversary to reach almost 60-80% of possible points within the target region in some cities. Such results are only a lower-bound, as an adversary can adjust our parameters to spend more resources (e.g., time) on the target source/destination than we did for our performance evaluations of thousands of paths. We propose countermeasures that limit an attacker's ability, without the need for any hardware modifications. Our system can be used as the foundation for countering such attacks, both detecting and recommending paths that are difficult to spoof.

Modern aircraft heavily rely on several wireless technologies for communications, control, and navigation. In this work, we demonstrate the vulnerability of aircraft instrument landing systems to wireless attacks. We show that it is possible to fully and in finegrain control the course deviation indicator, as displayed by the ILS receiver, in real-time, and demonstrate it on aviation-grade ILS receivers. We develop a tightly-controlled closed-loop ILS spoofer that autonomously adjusts the adversary's transmitted signals based on the aircraft's GPS location to cause an undetected off-runway landing. We demonstrate the integrated attack on an FAA certified flight-simulator (X-Plane)'s AI-based auto-land feature and show success rate with offset touchdowns of 18 meters to over 50 meters.

Low-power wide area networks (LPWANs), such as LoRa, are fast emerging as the preferred networking technology for large-scale Internet of Things deployments (e.g., smart cities). Due to long communication range and ultra low power consumption, LPWAN-enabled sensors are today being deployed in a variety of application scenarios where sensitive information is wirelessly transmitted. In this work, we study the privacy guarantees of LPWANs, in particular LoRa. We show that, although the event-based duty cycling of radio communication, i.e., transmission of radio signals only when an event occurs, saves power, it inherently leaks information. This information leakage is independent of the implemented crypto primitives. We identify two types of information leakage and show that it is hard to completely prevent leakage without incurring significant additional communication and computation costs.

Multilateration techniques have been proposed to verify the integrity of unprotected location claims in wireless localization systems. A common assumption is that the adversary is equipped with only a single device from which it transmits location spoofing signals. In this paper, we consider a more advanced model where the attacker is equipped with multiple devices and performs a geographically distributed coordinated attack on the multilateration system. The feasibility of a distributed multi-device attack is demonstrated experimentally with a self-developed attack implementation based on multiple COTS software-defined radio (SDR) devices. We launch an attack against the OpenSky Network, an air traffic surveillance system that implements a time-difference-of-arrival (TDoA) multi-lateration method for aircraft localization based on ADS-B signals. Our experiments show that the timing errors for distributed spoofed signals are indistinguishable from the multilateration errors of legitimate aircraft signals, indicating that the threat of multi-device spoofing attacks is real in this and other similar systems. In the second part of this work, we investigate physical-layer features that could be used to detect multi-device attacks. We show that the frequency offset and transient phase noise of the attacker's radio devices can be exploited to discriminate between a received signal that has been transmitted by a single (legitimate) transponder or by multiple (malicious) spoofing sources. Based on that, we devise a multi-device spoofing detection system that achieves zero false positives and a false negative rate below 1%.

Global Positioning System (GPS) is used ubiquitously in a wide variety of applications ranging from navigation and tracking to modern smart grids and communication networks. However, it has been demonstrated that modern GPS receivers are vulnerable to signal spoofing attacks. For example, today it is possible to change the course of a ship or force a drone to land in a hostile area by simply spoofing GPS signals. Several countermeasures have been proposed in the past to detect GPS spoofing attacks. These counter-measures offer protection only against naive attackers. They are incapable of detecting strong attackers such as those capable of seamlessly taking over a GPS receiver, which is currently receiving legitimate satellite signals, and spoofing them to an arbitrary location. Also, there is no hardware platform that can be used to compare and evaluate the effectiveness of existing countermeasures in real-world scenarios.

The Location Service (LCS) proposed by the telecommunication industry is an architecture that allows the location of mobile devices to be accessed in various applications. We explore the use of LCS in location-enhanced server authentication, which traditionally relies on certificates. Given recent incidents involving certificate authorities, various techniques to strengthen server authentication were proposed. They focus on improving the certificate validation process, such as pinning, revocation, or multi-path probing. In this paper, we propose using the server's geographic location as a second factor of its authenticity. Our solution, SALVE, achieves location-based server authentication by using secure DNS resolution and by leveraging LCS for location measurements. We develop a TLS extension that enables the client to verify the server's location in addition to its certificate. Successful server authentication therefore requires a valid certificate and the server's presence at a legitimate geographic location, e.g., on the premises of a data center. SALVE prevents server impersonation by remote adversaries with mis-issued certificates or stolen private keys of the legitimate server. We develop a prototype implementation and our evaluation in real-world settings shows that it incurs minimal impact to the average server throughput. Our solution is backward compatible and can be integrated with existing approaches for improving server authentication in TLS.

Today, contactless smart cards are used to provide physical access control and authentication in a wide variety of applications. Prior research have demonstrated the vulnerability of contactless smart cards to relay attacks. For example, an attacker can relay the communication between the card reader and the smart card to steal a car or pay for goods in a supermarket. To solve this problem, smart cards need to be enhanced with secure proximity verification, i.e., distance bounding, which enables the card reader and the card to verify their mutual distance. However, existing technologies do not support the deployment of distance bounding in such systems: NFC cannot provide sufficient distance resolution, and hardware complexity of the proposed (e.g., UWB-based) distance bounding radios prevents their use in contactless smart cards.

Power companies are deploying a multitude of sensors to monitor the energy grid. Measurements at different locations should be aligned in time to obtain the global state of the grid, and the industry therefore uses GPS as a common clock source. However, these sensors are exposed to GPS time spoofing attacks that cause misaligned aggregated measurements, leading to inaccurate monitoring that affects power stability and line fault contingencies. In this paper, we analyze the resilience of phasor measurement sensors, which record voltages and currents, to GPS spoofing performed by an adversary external to the system. We propose a solution that leverages the characteristics of multiple sensors in the power grid to limit the feasibility of such attacks. In order to increase the robustness of wide-area power grid monitoring, we evaluate mechanisms that allow collaboration among GPS receivers to detect spoofing attacks. We apply multilateration techniques to allow a set of GPS receivers to locate a false GPS signal source. Using simulations, we show that receivers sharing a local clock can locate nearby spoofing adversaries with sufficient confidence.

Wireless communication provides unique security challenges, but also enables novel ways to defend against attacks. In the past few years, a number of works discussed the use of friendly jamming to protect the confidentiality of the communicated data as well as to enable message authentication and access control. In this work, we analytically and experimentally evaluate the confidentiality that can be achieved by the use of friendly jamming, given an attacker with multiple receiving antennas. We construct a MIMO-based attack that allows the attacker to recover data protected by friendly jamming and refine the conditions for which this attack is most effective. Our attack shows that friendly jamming cannot provide strong confidentiality guarantees in all settings. We further test our attack in a setting where friendly jamming is used to protect the communication to medical implants.

The growing complexity and increased networking of security and safety-critical systems expose them to the risk of adversarial compromise through remote attacks. These attacks can result in full system compromise, but often the attacker gains control only over some system components (e.g., a peripheral) and over some applications running on the system. We consider the latter scenario and focus on enabling on-schedule execution of critical applications that are running on a partially compromised system --- we call this trusted scheduling. We identify the essential properties needed for the realization of a trusted scheduling system and we design an embedded system that achieves these properties. We show that our system protects not only against misbehaving applications but also against attacks by compromised peripherals. We evaluate the feasibility and performance of our system through a prototype implementation based on the AVR ATmega103 microcontroller.

Chirp signals have been extensively used in radar and sonar systems to determine distance, velocity and angular position of objects and in wireless communications as a spread spectrum technique to provide robustness and high processing gain. Recently, several standards have adopted chirp spread spectrum (CSS) as an underlying physical-layer scheme for precise, low-power and low-complexity real-time localization. While CSS-based ranging and localization solutions have been implemented and deployed, their security has so far not been analyzed.