fuzzing

Fuzzing between the lines in popular barcode software

Fuzzing—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 fuzzing

Fuzzing—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 […]

Curvance: Invariants unleashed

Welcome 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 […]

Continuously fuzzing Python C extensions

Deserializing, 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 […]

Improving the state of Cosmos fuzzing

Cosmos 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) recap

Last 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, […]

cURL audit: How a joke led to significant findings

In 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 wolfSSL

Trail 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 Echidna

(University of Queensland, Australia)
Smart 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-fuzz

During 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 fuzzer

During 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 Campaign

(Northern Arizona University)
In 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 Trace

Today, 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 reviewer

If 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 […]