VLDB 2026 Research / reviewers in the wild / expert
Abbas Acar
dblp:195/5992
· DBLP profile ↗
21ranked-venue papers
5as first author
16since 2021 · last 2026
0000-0002-4891-160XORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Security and privacy · 15 · 4 first-author · 10 since 2021Computer networks · 4 · 1 first-author · 4 since 2021Databases, data management, data science and information retrieval · 2 · 2 since 2021Applied, interdisciplinary, general and emerging computing · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Unveiling the Global Landscape of Android Security UpdatesabstractAndroid is the world's leading mobile operating system, with over three billion active devices. Detecting vulnerabilities and ensuring timely patch deployment are critical to maintaining security. The Android Open Source Project (AOSP) has enhanced the transparency of security updates through Security Patch Levels. However, challenges related to update speed and availability persist. In 2022, Google reported that half of the zero-day vulnerabilities discovered in the wild were variations of vulnerabilities that had already been patched. Recent research mainly highlights delays in update distribution, often attributing them to fragmentation and focusing primarily on flagship devices or limited time-frames. Our approach takes a device-centric perspective to investigate Android update patterns, analyzing 567K security update records from 2014 to 2024, covering 904 distinct devices from six key Original Equipment Manufacturers (OEMs) across 98 countries. Our extensive analysis revealed notable differences in update release timing across OEMs, device types, and regions. Our study also examines documented vulnerabilities and weaknesses, while assessing OEM compliance with Android security guidelines. Our study shows that$\sim$89.7% of vulnerabilities on unpatched Android devices are exploitable without user interaction and with low attack complexity. We also identified delays linked to fragmentation and OEM-specific challenges, and provide actionable insights for improvement. Haiyun Deng, Güliz Seray Tuncay, Abbas Acar, Esteban Luques, Harun Oz, Ahmet Aris, A. Selcuk Uluagac |
IEEE Trans. Dependable Secur. Comput. | 3 |
| 2025 | Speak Up, I'm Listening: Extracting Speech from Zero-Permission VR Sensors
Derin Cayir, Reham Mohamed Aburas, Riccardo Lazzeretti, Marco Angelini, Abbas Acar, Mauro Conti, Z. Berkay Celik, A. Selcuk Uluagac |
NDSS | 5 |
| 2025 | Ransomware Over Modern Web Browsers: A Novel Strain and a New Defense MechanismabstractRansomware is an increasingly prevalent form of malware targeting end-users, governments, and businesses. As it has evolved, adversaries added new capabilities to their arsenal. We propose a next-generation browser-based ransomware, RøB , which performs its malicious actions via web technologies, File System Access API (FSA) and WebAssembly (Wasm). RøB uses this API through the victims’ browsers; hence, it does not require the victims to download and install malicious binaries. We performed extensive evaluations with three different OSs, 23 file formats, 29 distinct directories, five cloud providers, and four antivirus solutions. Our evaluations show that RøB can encrypt various types of files in the local and cloud-integrated directories, external storage devices, and network-shared folders of victims. Our experiments also reveal that popular cloud solutions, Box Individual and Apple iCloud can be severely affected by RøB . Moreover, we conducted tests with commercial antivirus software such as AVG, Avast, Kaspersky, and Malware Bytes that perform sensitive directory and suspicious behavior monitoring against ransomware. We verified that RøB can evade these antivirus software and encrypt victim files. Moreover, existing ransomware detection solutions in the literature also cannot be a remedy against RøB due to its distinct features. Therefore, in this paper, we also propose RøBguard , a new detection system for RøB -like attacks. RøBguard monitors the web applications that use the FSA API via function hooking and uses a machine learning classifier to detect RøB -like attacks. We implemented a proof of concept version of RøBguard and our evaluation results show that RøBguard can detect RøB -like browser-based ransomware attacks effectively. We also provide future research directions that should be addressed in this domain. Harun Oz, Güliz Seray Tuncay, Ahmet Aris, Abbas Acar, Leonardo Babun, A. Selcuk Uluagac |
ACM Trans. Web | 4 |
| 2024 | Exploring Jamming and Hijacking Attacks for Micro Aerial DronesabstractRecent advancements in drone technology have shown that commercial off-the-shelf Micro Aerial Drones are more effective than large-sized drones for performing flight missions in narrow environments, such as swarming, indoor navigation, and inspection of hazardous locations. Due to their deployments in many civilian and military applications, safe and reliable communication of these drones throughout the mission is critical. The Crazyflie ecosystem is one of the most popular Micro Aerial Drones and has the potential to be deployed worldwide. In this paper, we empirically investigate two interference attacks against the Crazy Real Time Protocol (CRTP) implemented within the Crazyflie drones. In particular, we explore the feasibility of experimenting two attack vectors that can disrupt an ongoing flight mission: the jamming attack, and the hijacking attack. Our experimental results demonstrate the effectiveness of such attacks in both autonomous and non-autonomous flight modes on a Crazyflie 2.1 drone. Finally, we suggest potential shielding strategies that guarantee a safe and secure flight mission. To the best of our knowledge, this is the first work investigating jamming and hijacking attacks against Micro Aerial Drones, both in autonomous and non-autonomous modes. Yassine Mekdad, Abbas Acar, Ahmet Aris, Abdeslam El Fergougui, Mauro Conti, Riccardo Lazzeretti, A. Selcuk Uluagac |
ICC | 2 |
| 2024 | 50 Shades of Support: A Device-Centric Analysis of Android Security Updates
Abbas Acar, Güliz Seray Tuncay, Esteban Luques, Harun Oz, Ahmet Aris, A. Selcuk Uluagac |
NDSS | 1 |
| 2024 | EVOKE: Efficient Revocation of Verifiable Credentials in IoT Networks
Carlo Mazzocca, Abbas Acar, A. Selcuk Uluagac, Rebecca Montanari |
USENIX Security Symposium | 2 |
| 2024 | (In)Security of File Uploads in Node.jsabstractFile upload is a critical feature incorporated by a myriad of web applications in an effort to enable users to share and manage their files conveniently. It has been used in many useful services such as file-sharing and social media. While file upload is an essential component of web applications, the lack of rigorous checks on the file name, type, and content of the uploaded files can result in security issues, often referred to as Unrestricted File Upload (UFU). In this study, we analyze the (in)security of popular file upload libraries and real-world applications in the Node.js ecosystem. To automate our analysis, we propose and implement NodeSEC- a tool designed to analyze file upload insecurities in Node.js applications and libraries. NodeSEC generates unique payloads and thoroughly evaluates the application's file upload security against 13 distinct UFU-type attacks. Utilizing NodeSEC, we analyze the most popular file upload libraries and real-world applications in the Node.js ecosystem. Our analysis results reveal that some real-world web applications are vulnerable to UFU attacks and disclose serious security bugs in file upload libraries. As of this writing, we received 19 CVEs and two US-CERT cases for the security issues that we reported. Our findings provide strong evidence that dynamic features of Node.js applications introduce security shortcomings and that web developers should be cautious when implementing file upload features in their applications. Finally, combining our responsible disclosure experience and root cause analysis, we identified the main causes of significant security weaknesses in file uploads in Node.js. Harun Oz, Abbas Acar, Ahmet Aris, Güliz Seray Tuncay, Amin Kharraz, A. Selcuk Uluagac |
WWW | 2 |
| 2024 | A review of on-device machine learning for IoT: An energy perspective
Nazli Tekin, Ahmet Aris, Abbas Acar, A. Selcuk Uluagac, Vehbi C. Gungor |
Ad Hoc Networks | 3 |
| 2023 | Forensic Analysis of Cryptojacking in Host-Based Docker Containers Using HoneypotsabstractBlockchain-based cryptocurrencies have transformed financial transactions and created opportunities to profit from generating new coins through cryptomining. This has led to cybercriminals stealthily using their victim's computational power and resources for their own profit. Recent trends point to an increase in cryptojacking malware targeting devices with greater processing power such as host-based docker engines for faster and greater profit. In our study, we perform a forensic analysis for detecting cryptojacking (i.e., unauthorized cryptomining) in Docker containers using honeypots. Then, we present countermeasures for securing host-based Docker containers. In addition, we propose an approach for monitoring host-based Docker containers for cryptojacking detection. To the best of our knowledge, this is the first study investigating cryptojacking detection with the use of a honeypot system. Our results reveal that host resource usage and network traffic are the key indicators of possible unauthorized cryptomining in Docker containers. Javier Franco, Abbas Acar, Ahmet Aris, A. Selcuk Uluagac |
ICC | 2 |
| 2023 | RøB: Ransomware over Modern Web Browsers
Harun Oz, Ahmet Aris, Abbas Acar, Güliz Seray Tuncay, Leonardo Babun, A. Selcuk Uluagac |
USENIX Security Symposium | 3 |
| 2022 | The Truth Shall Set Thee Free: Enabling Practical Forensic Capabilities in Smart Environments
Leonardo Babun, Amit Kumar Sikder, Abbas Acar, A. Selcuk Uluagac |
NDSS | 3 |
| 2022 | A Lightweight IoT Cryptojacking Detection Mechanism in Heterogeneous Smart Home Networks
Ege Tekiner, Abbas Acar, A. Selcuk Uluagac |
NDSS | 2 |
| 2022 | A First Look at Code Obfuscation for WebAssemblyabstractWebAssembly (Wasm) has seen a lot of attention lately as it spreads through the mobile computing domain and becomes the new standard for performance-oriented web development. It has diversified its uses far beyond just web applications by acting as an execution environment for mobile agents, containers for IoT devices, and enabling new serverless approaches for edge computing. Within the numerous uses of Wasm, not all of them are benign. With the rise of Wasm-based cryptojacking malware, analyzing Wasm applications has been a hot topic in the literature, resulting in numerous Wasm-based cryptojacking detection systems. Many of these methods rely on static analysis, which traditionally can be circumvented through obfuscation. However, the feasibility of the obfuscation techniques for Wasm programs has never been investigated thoroughly. In this paper, we address this gap and perform the first look at code obfuscation for Wasm. We apply numerous obfuscation techniques to Wasm programs, and test their effectiveness in producing a fully obfuscated Wasm program. Particularly, we obfuscate both benign Wasm-based web applications and cryptojacking malware instances and feed them into a state-of-the-art Wasm cryptojacking detector to see if current Wasm analysis methods can be subverted with obfuscation. Our analysis shows that obfuscation can be highly effective and can cause even a state-of-the-art detector to misclassify the obfuscated Wasm samples. Shrenik Bhansali, Ahmet Aris, Abbas Acar, Harun Oz, A. Selcuk Uluagac |
WISEC | 3 |
| 2021 | SoK: Cryptojacking MalwareabstractEmerging blockchain and cryptocurrency-based technologies are redefining the way we conduct business in cyberspace. Today, a myriad of blockchain and cryp-tocurrency systems, applications, and technologies are widely available to companies, end-users, and even malicious actors who want to exploit the computational resources of regular users through cryptojacking malware. Especially with ready-to-use mining scripts easily provided by service providers (e.g., Coinhive) and untraceable cryptocurrencies (e.g., Monero), cryptojacking malware has become an indispensable tool for attackers. Indeed, the banking industry, major commercial websites, government and military servers (e.g., US Dept. of Defense), online video sharing platforms (e.g., Youtube), gaming platforms (e.g., Nintendo), critical infrastructure resources (e.g., routers), and even recently widely popular remote video conferencing/meeting programs (e.g., Zoom during the Covid-19 pandemic) have all been the victims of powerful cryptojacking malware campaigns. Nonetheless, existing detection methods such as browser extensions that protect users with blacklist methods or antivirus programs with different analysis methods can only provide a partial panacea to this emerging crypto-jacking issue as the attackers can easily bypass them by using obfuscation techniques or changing their domains or scripts frequently. Therefore, many studies in the literature proposed cryptojacking malware detection methods using various dynamic/behavioral features. However, the literature lacks a systemic study with a deep understanding of the emerging cryptojacking malware and a comprehensive review of studies in the literature. To fill this gap in the literature, in this SoK paper, we present a systematic overview of cryptojacking malware based on the information obtained from the combination of academic research papers, two large cryptojacking datasets of samples, and 45 major attack instances. Finally, we also present lessons learned and new research directions to help the research community in this emerging area. Ege Tekiner, Abbas Acar, A. Selcuk Uluagac, Engin Kirda, Ali Aydin Selçuk |
EuroS&P | 2 |
| 2021 | A Lightweight Privacy-Aware Continuous Authentication Protocol-PACAabstractAs many vulnerabilities of one-time authentication systems have already been uncovered, there is a growing need and trend to adopt continuous authentication systems. Biometrics provides an excellent means for periodic verification of the authenticated users without breaking the continuity of a session. Nevertheless, as attacks to computing systems increase, biometric systems demand more user information in their operations, yielding privacy issues for users in biometric-based continuous authentication systems. However, the current state-of-the-art privacy technologies are not viable or costly for the continuous authentication systems, which require periodic real-time verification. In this article, we introduce a novel, lightweight, privacy-aware, and secure continuous authentication protocol called PACA. PACA is initiated through a password-based key exchange (PAKE) mechanism, and it continuously authenticates users based on their biometrics in a privacy-aware manner. Then, we design an actual continuous user authentication system under the proposed protocol. In this concrete system, we utilize a privacy-aware template matching technique and a wearable-assisted keystroke dynamics-based continuous authentication method. This provides privacy guarantees without relying on any trusted third party while allowing the comparison of noisy user inputs (due to biometric data) and yielding an efficient and lightweight protocol. Finally, we implement our system on an Apple smartwatch and perform experiments with real user data to evaluate the accuracy and resource consumption of our concrete system. Abbas Acar, Shoukat Ali, Koray Karabina, Cengiz Kaygusuz, Hidayet Aksu, Kemal Akkaya, A. Selcuk Uluagac |
ACM Trans. Priv. Secur. | 1 |
| 2021 | A Usable and Robust Continuous Authentication Framework Using WearablesabstractOne-time login process in conventional authentication systems does not guarantee that the identified user is the actual user throughout the session. However, it is necessary to re-verify the user identity periodically throughout a login session, which is lacking in existing one-time login systems. Continuous authentication, which re-verifies the user identity without breaking the continuity of the session, can address this issue. However, existing methods for Continuous Authentication are either not reliable or not usable. In this paper, we introduce a usable and reliable Wearable-Assisted Continuous Authentication (WACA), which relies on the sensor-based keystroke dynamics and the authentication data is acquired through the built-in sensors of a wearable (e.g., smartwatch) while the user is typing. The acquired data is periodically and transparently compared with the registered profile of the initially logged-in user with one-way classifiers. With this, WACA continuously ensures that the current user is the user who logged-in initially. We implemented the WACA framework and evaluated its performance extensively on real devices with real users. The empirical evaluation of WACA reveals that WACA is feasible, and its error rate is as low as 1 percent with 30 seconds of processing time and 2-3 percent for 20 seconds. The computational overhead is minimal. Furthermore, WACA is capable of identifying insider threats with very high accuracy (99.2 percent) and also robust against powerful adversaries such as imitation and statistical attackers. We believe that this work has practical and far-reaching implications for the future of the usable authentication field. Abbas Acar, Hidayet Aksu, A. Selcuk Uluagac, Kemal Akkaya |
IEEE Trans. Mob. Comput. | 1 |
| 2020 | Peek-a-boo: i see your smart home activities, even encrypted!abstractA myriad of IoT devices such as bulbs, switches, speakers in a smart home environment allow users to easily control the physical world around them and facilitate their living styles through the sensors already embedded in these devices. Sensor data contains a lot of sensitive information about the user and devices. However, an attacker inside or near a smart home environment can potentially exploit the innate wireless medium used by these devices to exfiltrate sensitive information from the encrypted payload (i.e., sensor data) about the users and their activities, invading user privacy. With this in mind, in this work, we introduce a novel multi-stage privacy attack against user privacy in a smart environment. It is realized utilizing state-of-the-art machine-learning approaches for detecting and identifying the types of IoT devices, their states, and ongoing user activities in a cascading style by only passively sniffing the network traffic from smart home devices and sensors. The attack effectively works on both encrypted and unencrypted communications. We evaluate the efficiency of the attack with real measurements from an extensive set of popular off-the-shelf smart home IoT devices utilizing a set of diverse network protocols like WiFi, ZigBee, and BLE. Our results show that an adversary passively sniffing the traffic can achieve very high accuracy (above 90%) in identifying the state and actions of targeted smart home devices and their users. To protect against this privacy leakage, we also propose a countermeasure based on generating spoofed traffic to hide the device states and demonstrate that it provides better protection than existing solutions. Abbas Acar, Hossein Fereidooni, Tigist Abera, Amit Kumar Sikder, Markus Miettinen, Hidayet Aksu, Mauro Conti, Ahmad-Reza Sadeghi, A. Selcuk Uluagac |
WISEC | 1 |
| 2020 | Kratos: multi-user multi-device-aware access control system for the smart homeabstractIn a smart home system, multiple users have access to multiple devices, typically through a dedicated app installed on a mobile device. Traditional access control mechanisms consider one unique trusted user that controls the access to the devices. However, multi-user multi-device smart home settings pose fundamentally different challenges to traditional single-user systems. For instance, in a multi-user environment, users have conflicting, complex, and dynamically changing demands on multiple devices, which cannot be handled by traditional access control techniques. To address these challenges, in this paper, we introduce Kratos, a novel multi-user and multi-device-aware access control mechanism that allows smart home users to flexibly specify their access control demands. Kratos has three main components: user interaction module, back-end server, and policy manager. Users can specify their desired access control settings using the interaction module which are translated into access control policies in the backend server. The policy manager analyzes these policies and initiates negotiation between users to resolve conflicting demands and generates final policies. We implemented Kratos and evaluated its performance on real smart home deployments featuring multi-user scenarios with a rich set of configurations (309 different policies including 213 demand conflicts and 24 restriction policies). These configurations included five different threats associated with access control mechanisms. Our extensive evaluations show that Kratos is very effective in resolving conflicting access control demands with minimal overhead, and robust against different attacks. Amit Kumar Sikder, Leonardo Babun, Z. Berkay Celik, Abbas Acar, Hidayet Aksu, Patrick D. McDaniel, Engin Kirda, A. Selcuk Uluagac |
WISEC | 4 |
| 2019 | Curie: Policy-based Secure Data ExchangeabstractData sharing among partners---users, companies, organizations---is crucial for the advancement of collaborative machine learning in many domains such as healthcare, finance, and security. Sharing through secure computation and other means allow these partners to perform privacy-preserving computations on their private data in controlled ways. However, in reality, there exist complex relationships among members (partners). Politics, regulations, interest, trust, data demands and needs prevent members from sharing their complete data. Thus, there is a need for a mechanism to meet these conflicting relationships on data sharing. This paper presents, an approach to exchange data among members who have complex relationships. A novel policy language, CPL, that allows members to define the specifications of data exchange requirements is introduced. With CPL, members can easily assert who and what to exchange through their local policies and negotiate a global sharing agreement. The agreement is implemented in a distributed privacy-preserving model that guarantees sharing among members will comply with the policy as negotiated. The use of Curie is validated through an example healthcare application built on recently introduced secure multi-party computation and differential privacy frameworks, and policy and performance trade-offs are explored. Z. Berkay Celik, Abbas Acar, Hidayet Aksu, Ryan Sheatsley, Patrick D. McDaniel, A. Selcuk Uluagac |
CODASPY | 2 |
| 2019 | An Analysis of Malware Trends in Enterprise Networks
Abbas Acar, Long Lu, A. Selcuk Uluagac, Engin Kirda |
ISC | 1 |
| 2019 | A digital forensics framework for smart settings: posterabstractUsers utilize IoT devices and sensors in a co-operative manner to enable the concept of a smart environment. This integration generate data with high forensic value. Nonetheless, current smart app programming platforms do not provide any digital forensics capability to identify, trace, store, and analyze the data produced in these settings. To overcome these limitations, in this poster, we present our ongoing work to introduce a novel digital forensic framework for a smart environment. Leonardo Babun, Amit Kumar Sikder, Abbas Acar, A. Selcuk Uluagac |
WiSec | 3 |