Search arXivSearch

arXiv subjects

Aravind Kumar Machiry

Publications and source records attributed to Aravind Kumar Machiry.

2 recordsLinked to original sources

Speed Kills: Exploring Confused Deputy Attacks Through Edge AI Accelerators

AI Accelerators (AIAs) are specialized hardware, such as Tensor Processing Units (TPUs), that enable optimal and efficient execution of AI applications and on-device inference. The growing demand for AI applications has led to the widespread adoption of AIAs on edge and embedded devices. Unlike applications, AIAs are not bound by Operating System (OS) restrictions and have limited visibility into Application Processor (AP) security mechanisms (e.g., kernel versus application memory and process isolation). This semantic gap can lead to confused deputy vulnerabilities, where an AIA can be tricked by a malicious application into performing privileged operations on its behalf. In this paper, we conduct the first in-depth study of Confused Deputy Attacks (CDAs) using AIAs. We design DeputyHunt, a Large Language Model (LLM)-assisted framework to extract CDA-relevant information for a given AIA through a combination of dynamic and static analysis. We use this information to explore the feasibility of CDAs on seven different AIAs from popular vendors, including Google, NVIDIA, Hailo, Texas Instruments, NXP, AWS, and Rockchip. Our analysis reveals that CDAs are feasible on six out of the seven AIAs, impacting over 128 System-on-Chips (SoCs) and over 100 million devices. Our findings highlight critical security risks posed by AIAs to system security. Our work has been acknowledged by the corresponding vendors and assigned CVE-2025-66425. We propose an on-demand validation defense against CDAs, and our evaluation on the Gem5-salam simulator shows that the average runtime overhead of our mechanism is significantly lower (~15% versus ~56%) than that of traditional defenses.

cs.CR

LEMIX: Enabling Testing of Embedded Applications as Linux Applications (Extended Report)

Dynamic analysis, through rehosting, is an important capability for security assessment in embedded systems software. Existing rehosting techniques aim to provide high-fidelity execution by accurately emulating hardware and peripheral interactions. However, these techniques face challenges in adoption due to the increasing number of available peripherals and the complexities involved in designing emulation models for diverse hardware. Additionally, contrary to the prevailing belief that guides existing works, our analysis of reported bugs shows that high-fidelity execution is not required to expose most bugs in embedded software. Our key hypothesis is that security vulnerabilities are more likely to arise at higher abstraction levels. To substantiate our hypothesis, we introduce LEMIX, a framework enabling dynamic analysis of embedded applications by rehosting them as x86 Linux applications decoupled from hardware dependencies. Enabling embedded applications to run natively on Linux facilitates security analysis using available techniques and takes advantage of the powerful hardware available on the Linux platform for higher testing throughput. We develop various techniques to address the challenges involved in converting embedded applications to Linux applications. We evaluated LEMIX on 18 real-world embedded applications across four RTOSes and found 21 new bugs in 12 of the applications and all 4 of the RTOS kernels. We report that LEMIX is superior to existing state-of-the-art techniques both in terms of code coverage (~2x more coverage) and bug detection (18 more bugs).

cs.CR