Blockchain

A mistake in the bulletproofs paper could have led to the theft of millions of dollars

Jim Miller
We discovered a critical vulnerability in Incognito Chain that would allow an attacker to mint arbitrary tokens and drain user funds. Incognito offers confidential transactions through zero-knowledge proofs, so an attacker could have stolen millions of dollars of shielded funds without ever being detected or identified. The vulnerability stemmed from an insecure […]

Fuzzing on-chain contracts with Echidna

Elvis Skozdopolj, Guillermo Larregay
With 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 […]

Evaluating blockchain security maturity

Josselin Feist, Blockchain Engineering Director
Holistic security reviews should reveal far more than simple bugs. Often, these bugs indicate deeper issues that can be challenging to understand and address. Given the time-boxed nature of reviews, security engineers may not have the opportunity to identify all bugs caused by these problems—and they may continue to […]

What we told the CFTC about blockchain threats

In March, I joined the Commodity Futures Trading Commission’s Technology Advisory Committee (TAC), helping the regulatory agency navigate the complexities of cybersecurity risks, particularly in emerging technologies like AI and blockchain. During the committee’s first meeting, I discussed how the rapidly changing and public nature of blockchain technology makes it uniquely susceptible […]

Differential fuzz testing upgradeable smart contracts with Diffusc

William Bodell
On 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 […]

What should governments consider when getting involved with blockchain?

Trail of Bits
Last September, Principal Security Engineer Dr. Evan Sultanik was on a panel hosted by the Naval Postgraduate School’s Distributed Consensus: Blockchain & Beyond (DC:BB) movement, where faculty and students there are seeking opportunities to learn and share knowledge, research, funding, and events focused on distributed consensus technologies. The panel of nine government, academia, and industry […]

Circomspect has more passes!

Fredrik Dahlgren
TL;DR: We have released version 0.8.0 of Circomspect, our static analyzer and linter for Circom. Since our initial release of Circomspect in September 2022, we have added five new analysis passes, support for tags, tuples, and anonymous components, links to in-depth descriptions of each identified issue, and squashed a […]

Reusable properties for Ethereum contracts

Trail of Bits
As smart contract security constantly evolves, property-based fuzzing has become a go-to technique for developers and security engineers. This technique relies on the creation of code properties – often called invariants – which describe what the code is supposed to do. To help the community define properties, we are releasing a set of 168 pre-built […]

Hybrid fuzzing: Sharpening the spikes of Echidna

Tom Malcolm, 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 […]

It pays to be Circomspect

Fredrik Dahlgren
In October 2019, a security researcher found a devastating vulnerability in Tornado.cash, a decentralized, non-custodial mixer on the Ethereum network. Tornado.cash uses zero-knowledge proofs (ZKPs) to allow its users to privately deposit and withdraw funds. The proofs are supposed to guarantee that each withdrawal can be matched against a […]

Using mutants to improve Slither

Alex Groce, Northern Arizona University
Improving static analysis tools can be hard; once you’ve implemented a good tool based on a useful representation of a program and added a large number of rules to detect problems, how do you further enhance the tool’s bug-finding power? One (necessary) approach to coming up with new rules […]

Shedding smart contract storage with Slither

Troy Sargent
You think you’ve found a critical bug in a Solidity smart contract that, if exploited, could drain a widely used cryptocurrency exchange’s funds. To confirm that it’s really a bug, you need to figure out the value at an obscure storage slot that has no getter method. Adrenaline courses […]