arXiv subjects

Seungjin Baek

Publications and source records attributed to Seungjin Baek.

4 recordsLinked to original sources

arXiv2026

Towards Operator-Empowered Vulnerability Hotfixing for 5G Radio Access Networks

Cellular protocol vulnerabilities can remain exploitable for months or years while standards bodies, vendors, and mobile network operators (MNOs) coordinate permanent fixes. We present Buckler, a framework that enables an MNO to deploy temporary, local, and reversible hotfixes in its radio access network (RAN) during this exposure window. Buckler places reusable hooks at standardized L2/L3 channel boundaries and exposes a closed, stateful match-action interface with three preventive actions: DROP, MODIFY, and RELEASE. We evaluate whether this bounded design provides useful coverage without requiring extensive changes to existing RANs. From 23 papers, we identify 64 attacks rooted in standard L2/L3 protocol behavior, of which 43 provide a preventive intervention point at the RAN, and we construct Buckler hotfixes for 20 of them. All 20 hotfixes use the same rule vocabulary and only five standardized channel hooks, while the unsupported attacks expose endpoint dependencies that a RAN cannot satisfy alone. We implement the five hooks on srsRAN and OpenAirInterface with small, structurally similar changes, and demonstrate all three actions against representative availability and privacy attacks. These results establish operator-empowered hotfixing as a practical and portable interim defense and delineate the architectural limits of RAN-only prevention.

cs.CR↗

arXiv2026

The Vehicle May Be Sick: Denial of Diagnostic Services by Exploiting the CAN Transport Protocol

Vehicle diagnostics has become essential for detecting in-vehicle errors and ensuring safety. While the Unified Diagnostic Services (UDS) protocol is widely adopted for diagnostic operations, it relies on the ISO 15765-2 standard as the transport protocol over the Controller Area Network (CAN), which was designed without inherent security considerations. In this paper, we identify eight novel attack scenarios that exploit specific transport layer mechanisms in the ISO 15765-2 standard, including Flow Control manipulation, Sequence Number violations, and error handling abuses. We evaluate these attacks on a real passenger vehicle using two distinct diagnostic tools to demonstrate their practical impact. Our results confirm that three of these attack scenarios successfully induce denial of diagnostic services, leading to abnormal diagnostic results such as concealed faults and manipulated sensor readings. These findings highlight critical vulnerabilities that can deceive technicians and drivers, potentially exposing vehicles to significant safety risks.

cs.CR↗

arXiv2024

Publicly Shareable Clinical Large Language Model Built on Synthetic Clinical Notes

The development of large language models tailored for handling patients' clinical notes is often hindered by the limited accessibility and usability of these notes due to strict privacy regulations. To address these challenges, we first create synthetic large-scale clinical notes using publicly available case reports extracted from biomedical literature. We then use these synthetic notes to train our specialized clinical large language model, Asclepius. While Asclepius is trained on synthetic data, we assess its potential performance in real-world applications by evaluating it using real clinical notes. We benchmark Asclepius against several other large language models, including GPT-3.5-turbo and other open-source alternatives. To further validate our approach using synthetic notes, we also compare Asclepius with its variants trained on real clinical notes. Our findings convincingly demonstrate that synthetic clinical notes can serve as viable substitutes for real ones when constructing high-performing clinical language models. This conclusion is supported by detailed evaluations conducted by both GPT-4 and medical professionals. All resources including weights, codes, and data used in the development of Asclepius are made publicly accessible for future research. (https://github.com/starmpcc/Asclepius)

cs.CL↗

arXiv2012

Constructions by ruler and compass, together with a fixed conic

It is well-known to be impossible to trisect an arbitrary angle and duplicate an arbitrary cube by a ruler and a compass. On the other hand, it is known from the ancient times that these constructions can be performed when it is allowed to use several conic curves. In this paper, we prove that any point constructible from conics can be constructed using a ruler and a compass, together with a single fixed non-degenerate conic different from a circle.

math.HO↗