Introducing a new section on snapshot fuzzing for kernel-level testing in the Testing HandbookLearn snapshot fuzzing for kernel-level testing. New Testing Handbook section shows how to test drivers, antivirus software, and complex kernel components.
Unleashing Medusa: Fast and scalable smart contract fuzzingIntroducing Medusa v1, a cutting-edge fuzzing framework designed to enhance smart contract security.
Fuzzing between the lines in popular barcode softwareFuzzing—one of the most successful techniques for finding security bugs, consistently featured in articles and industry conferences—has become so popular that you may think most important software has already been extensively fuzzed. But that’s not always the case. In this blog post, we show how we fuzzed the ZBar barcode scanning library […]
Finding mispriced opcodes with fuzzingFuzzing—a testing technique that tries to find bugs by repeatedly executing test cases and mutating them—has traditionally been used to detect segmentation faults, buffer overflows, and other memory corruption vulnerabilities that are detectable through crashes. But it has additional uses you may not know about: given the right invariants, we can use […]
Understanding AddressSanitizer: Better memory safety for your codeThis post will guide you through using AddressSanitizer (ASan), a compiler plugin that helps developers detect memory issues in code that can lead to remote code execution attacks (such as WannaCry or this WebP implementation bug). ASan inserts checks around memory accesses during compile time, and crashes the program […]
Using benchmarks to speed up EchidnaDuring my time as a Trail of Bits associate last summer, I worked on optimizing the performance of Echidna, Trail of Bits’ open-source smart contract fuzzer, written in Haskell. Through extensive use of profilers and other tools, I was able to pinpoint and debug a massive space leak in one of Echidna’s […]
Curvance: Invariants unleashedWelcome to our deep dive into the world of invariant development with Curvance. We’ve been building invariants as part of regular code review assessments for more than 6 years now, but our work with Curvance marks our very first official invariant development project, in which developing and testing invariants is all we […]
Introducing Ruzzy, a coverage-guided Ruby fuzzerTrail of Bits is excited to introduce Ruzzy, a coverage-guided fuzzer for pure Ruby code and Ruby C extensions. Fuzzing helps find bugs in software that processes untrusted input. In pure Ruby, these bugs may result in unexpected exceptions that could lead to denial of service, and in Ruby C extensions, they […]
Why fuzzing over formal verification?We recently introduced our new offering, invariant development as a service. A recurring question that we are asked is, “Why fuzzing instead of formal verification?” And the answer is, “It’s complicated.” We use fuzzing for most of our audits but have used formal verification methods in the […]
How we applied advanced fuzzing techniques to cURLNear the end of 2022, Trail of Bits was hired by the Open Source Technology Improvement Fund (OSTIF) to perform a security assessment of the cURL file transfer command-line utility and its library, libcurl. The scope of our engagement included a code review, a threat model, and the subject of this blog […]
Continuously fuzzing Python C extensionsDeserializing, decoding, and processing untrusted input are telltale signs that your project would benefit from fuzzing. Yes, even Python projects. Fuzzing helps reduce bugs in high-assurance software developed in all programming languages. Fortunately for the Python ecosystem, Google has released Atheris, a coverage-guided fuzzer for both pure Python code and Python C […]
Master fuzzing with our new Testing Handbook chapterOur latest addition to the Trail of Bits Testing Handbook is a comprehensive guide to fuzzing: an essential, effective, low-effort method to find bugs in software that involves repeatedly running a program with random inputs to cause unexpected results.
Improving the state of Cosmos fuzzingCosmos is a platform enabling the creation of blockchains in Go (or other languages). Its reference implementation, Cosmos SDK, leverages strong fuzz testing extensively, following two approaches: smart fuzzing for low-level code, and dumb fuzzing for high-level simulation. In this blog post, we explain the differences between these approaches and show how […]
Chaos Communication Congress (37C3) recapLast month, two of our engineers attended the 37th Chaos Communication Congress (37C3) in Hamburg, joining thousands of hackers who gather each year to exchange the latest research and achievements in technology and security. Unlike other tech conferences, this annual gathering focuses on the interaction of technology and society, covering such topics as politics, entertainment, […]
Introducing invariant development as a serviceUnderstanding and rigorously testing system invariants are essential aspects of developing robust smart contracts. Invariants are facts about the protocol that should remain true no matter what happens. Defining and testing these invariants allows developers to prevent the introduction of bugs and make their code more robust in the long term. However, it is difficult […]
Fuzzing on-chain contracts with EchidnaWith the release of version 2.1.0 of Echidna, our fuzzing tool for Ethereum smart contracts, we’ve introduced new features for direct retrieval of on-chain data, such as contract code and storage slot values. This data can be used to fuzz deployed contracts in their on-chain state or to test […]
Differential fuzz testing upgradeable smart contracts with DiffuscOn March 28, 2023, SafeMoon, a self-styled “community-focused DeFi token” on Binance Smart Chain, lost the equivalent of $8.9 million in Binance Coin BNB to an exploit in a liquidity pool. The exploit leveraged a simple error introduced in an upgrade to SafeMoon’s SFM token contract, allowing the attacker to burn tokens held in the […]
cURL audit: How a joke led to significant findingsIn fall 2022, Trail of Bits audited cURL, a widely-used command-line utility that transfers data between a server and supports various protocols. The project coincided with a Trail of Bits maker week, which meant that we had more manpower than we usually do, allowing us to take a nonstandard approach to the […]
Keeping the wolves out of wolfSSLTrail of Bits is publicly disclosing four vulnerabilities that affect wolfSSL: CVE-2022-38152, CVE-2022-38153, CVE-2022-39173, and CVE-2022-42905. The four issues, which have CVSS scores ranging from medium to critical, can all result in a denial of service (DoS). These vulnerabilities have been discovered automatically using the novel protocol fuzzer tlspuffin. This blog post […]
Hybrid fuzzing: Sharpening the spikes of EchidnaSmart contract fuzzing is an effective bug-finding technique that is largely used at Trail Of Bits during audits. During my internship at Trail of Bits, I contributed to expand our fuzzing capabilities by working on Hybrid Echidna, a “hybrid fuzzer” that couples our smart contract fuzzer, Echidna, with […]
Improving the state of go-fuzzDuring my winternship, I used the findings from recent Go audits to make several improvements to go-fuzz, a coverage-based fuzzer for projects written in Go. I focused on three enhancements to improve the effectiveness of Go fuzzing campaigns and provide a better experience for users. I contributed to fixing type alias […]
Optimizing a smart contract fuzzerDuring my winternship, I applied code analysis tools, such as GHC’s Haskell profiler, to improve the efficiency of the Echidna smart contract fuzzer. As a result, Echidna is now over six times faster! Echidna overview To use Echidna, users provide smart contracts and a list of conditions that should be satisfied no […]
A Year in the Life of a Compiler Fuzzing CampaignIn the summer of 2020, we described our work fuzzing the Solidity compiler, solc. So now we’d like to revisit this project, since fuzzing campaigns tend to “saturate,” finding fewer new results over time. Did Solidity fuzzing run out of gas? Is fuzzing a high-stakes project worthwhile, especially if […]
Un-bee-lievable Performance: Fast Coverage-guided Fuzzing with Honeybee and Intel Processor TraceToday, we are releasing an experimental coverage-guided fuzzer called Honeybee that records program control flow using Intel Processor Trace (IPT) technology. Previously, IPT has been scrutinized for severe underperformance due to issues with capture systems and inefficient trace analyses. My winter internship focused on working through these challenges to make […]
Confessions of a smart contract paper reviewerIf you’re thinking of writing a paper describing an exciting novel approach to smart contract analysis and want to know what reviewers will be looking for, you’ve come to the right place. Deadlines for many big conferences (ISSTA tool papers, ASE, FSE, etc.) are approaching, as is our own Workshop on Smart Contract Analysis, so […]
