Tag: Security

The difference of overflow and underflow

  • Haco
  • December 22, 2025
  • 3 min read

In computer science—and specifically in fuzzing and exploitation—the terms Overflow and Underflow mean different things depending on whether you are talking about Numbers (Arithmetic) or Memory (Buffers). Here is the breakdown of the differences. 1. Arithmetic (Integer) Context This refers to the value of a number going beyond what the variable type can hold. Integer Overflow (Too Big) Occurs when you try to store a value larger than the maximum limit. The value "wraps around" to the minimum. Analogy: A car odometer at 999,999 rolling over to 000,000.…

Keynote: Perspectives on Trust in Hardware Supply Chains

  • Haco
  • September 30, 2025
  • 3 min read

This talk, titled "Keynote: Perspectives on Trust in Hardware Supply Chains" [] by Bunny Huang, discusses the complexities and vulnerabilities within hardware supply chains. Key points from the talk include: Diversification and Simplification: In chaotic times, it's beneficial to diversify by having multiple, hyper-efficient locations rather than centralized single points of failure. Simplifying business processes and legal contracts can reduce complexity and improve understanding for everyone involved []. Trust in Hardware: The speaker suggests moving the "root of trust" or "source of truth" into hardware, such as using…

Tinker Tailor LLM Spy: Investigate & Respond to Attacks on GenAI Chatbots

  • Haco
  • September 25, 2025
  • 3 min read

In the "Tinker Tailor LLM Spy: Investigate & Respond to Attacks on GenAI Chatbots" talk by Black Hat, Ellen Scott discusses the increasing ubiquity of Generative AI chatbots and the security incidents that can arise from their misuse. The talk outlines three main incident scenarios and provides a playbook for investigation and response []. Here's a summary of the key takeaways: Chatbot Risk Classification []: Low Risk: Chatbots providing general information (e.g., a weather chatbot). Incidents primarily involve brand damage, like a chatbot giving Taylor Swift-themed weather reports…

Running the “Reflections on Trusting Trust” Compiler

  • Haco
  • September 9, 2025
  • 26 min read

Supply chain security is a hot topic today, but it is a very old problem. In October 1983, 40 years ago this week, Ken Thompson chose supply chain security as the topic for his Turing award lecture, although the specific term wasn’t used back then. (The field of computer science was still young and small enough that the ACM conference where Ken spoke was the “Annual Conference on Computers.”) Ken’s lecture was later published in Communications of the ACM under the title “.” It is a classic paper, and a…

Microarchitecture Vulnerabilities: Past, Present, and Future

  • Haco
  • September 4, 2025
  • 1 min read

Past Present Logic Issues Exploitation Techniques Physical Domain in Software Mitigation Efforts Physical hardware cannot be changed in the field Vendors build in "Survivability features" Microcode is the most common used tool for mitigations Other firmware is also used "Chicken bits" to disable / change behavior Some issues are best mitigated in software Mitigations are not always possible/reasonable and almost difficult and time-consuming to engineer Prevention Pre-silicon Post-silicon Future Take Aways

SysBumps: Exploiting Speculative Execution in System Calls

  • Haco
  • September 2, 2025
  • 3 min read

The video presents an attack technique called SysBumps, demonstrated by researchers Hyerean Jang, Taehun Kim, and Youngjoo Shin at Black Hat Europe 2024. Here’s what it’s about: What SysBumps DoesSysBumps breaks Kernel Address Space Layout Randomization (KASLR) on macOS systems running on Apple Silicon, including M-series chips. It uses speculative execution within system calls, triggering side-channel behaviors that allow an unprivileged attacker to detect kernel memory layout. How the Attack WorksBy system calls that involve speculative execution, attackers can influence the translation lookaside buffer (TLB). This manipulation allows…

Bypassing ARM’s Memory Tagging Extension with a Side-Channel Attack

  • Haco
  • September 2, 2025
  • 2 min read

This explains a research project on how to bypass ARM's Memory Tagging Extension (MTE), a hardware feature designed to prevent memory corruption vulnerabilities. Here are the key takeaways: ARM MTE: MTE works like a "lock and key" system. Pointers have a "key" (a 4-bit tag) and memory objects have a "lock" (also a 4-bit tag). If the key and lock don't match when a pointer tries to access memory, the program will crash, preventing an attack. The Challenge: The tags are randomly generated, making it difficult for an…

Uncovering Supply Chain Attack with Code Genome Framework

  • Haco
  • September 2, 2025
  • 2 min read

This talk from IBM Research focuses on using AI and machine learning to combat supply chain attacks. The presenters highlight the increasing lack of trust in software due to major security breaches like the XZ backdoor. Here are the key takeaways: The Problem: There's a "semantic gap" between what code is expected to do and what it actually does. This gap is exploited in supply chain attacks where malicious code is hidden in software updates or open-source projects. The Solution: The researchers introduce the "Code Genome Framework," an…

The Devil is in the (Micro-) Architectures: Uncovering New Side-Channel and Bit-Flip Attack Surfaces

  • Haco
  • September 2, 2025
  • 2 min read

Jolio and Yenzo discusses new attack vectors on Deep Neural Network (DNN) executables, specifically focusing on side-channel and bit-flip vulnerabilities. Here's a summary of the key points: DNN Executables and Vulnerabilities: The talk begins by explaining that cloud service providers deploy machine learning models as valuable services. Attackers can exploit side-channels to learn about the architecture of these models, which then opens the door for other attacks. The speakers investigate if DNN executables, created through deep learning compilation for performance, are also vulnerable. Deep Compilation and Side-Channels: Deep…

Arbitrary Data Manipulation and Leakage with CPU Zero-Day Bugs on RISC-V

  • Haco
  • September 2, 2025
  • 2 min read

Fabian Thomas and Laurent Schmierer, introduces "GhostRider," a zero-day vulnerability they discovered in the T-Head C910 RISC-V processor. This vulnerability allows for data manipulation and leakage by bypassing software isolation and writing directly to physical memory. Here are the key points discussed: GhostRider Vulnerability: This exploit allows unprivileged applications to bypass operating systems and other security measures to interact directly with hardware. It exploits a flaw in a RISC-V vector instruction to write to physical memory instead of virtual memory, enabling arbitrary data manipulation, memory leakage, and privilege…