Prime Picks for Sensible Contract Safety Instruments in 2023


Learn Time: 7 minutes

It’s time to dig into the thrilling realm of sensible contract safety!

The information doesn’t lie. To place it bluntly, a whopping $13B in crypto property was misplaced to web3 hacks because of sensible contract vulnerabilities between 2016 and 2023.

If we take a more in-depth take a look at these incidents, many of those hacks happen because of some evident points: unhealthy logic, lacking enter validation, and ever-elusive sensible contract flaws.

In different phrases, these gaps in sensible contract safety favour opportunistic attackers to search out their method in.

We’re right here to inform you that assistance is at hand – within the type of sensible contract safety instruments. That’s the core theme of our article, and we’ll discover how these instruments may help you securely construct in web3. 

A Holistic View of Sensible Contract Safety

To underscore the significance of auditing, let’s carry some compelling information into the highlight. Once we look at the safety panorama of web3, over 51% of tasks that fell sufferer to hacks hadn’t undergone any type of audit. 

Auditing is the gold customary when it comes to sensible contract safety. It gives a sturdy defence in opposition to vulnerabilities, instilling belief in your tasks. 

Additionally, we are able to’t overlook the truth that guide audits may be time-consuming and dear. That’s the place sensible contract safety instruments come into play.

These instruments aren’t a substitute for audits however provide an additional layer of safety by catching potential points early within the improvement course of. They act as vigilant gatekeepers, scanning your code for errors from the get-go. 

With this mix of auditing and automatic safety instruments, you’ll be able to guarantee a baseline stage of safety in the course of the deployment of your sensible contracts.

Nevertheless, web3 safety is an ongoing course of and requires steady vigilance. That’s the place these instruments come in useful and may be leveraged anytime to make sure digital safety.

So, within the subsequent part, we’ll break down how sensible contracts are assessed for vulnerabilities by means of numerous testing strategies, leveraging a variety of safety instruments.

Prime 10 Sensible Contract Safety Instruments And Testing Strategies

This part will dive right into a complete listing of the assessments and particular instruments employed for sensible contract assessments.

1. Static Evaluation- is a safety testing technique that examines the supply code of sensible contracts with out executing them. It goals to determine potential vulnerabilities, coding errors, and safety points.

Goal:  Early detection of points within the code with out operating the contract.

Safety Testing Instruments: Slither, MythX


Slither is a Python-based static evaluation device for sensible contract evaluation.


  • Detects vulnerabilities like reentrancy assaults, timestamp dependency points, and integer overflow vulnerabilities.
  • Person-friendly and straightforward to make use of.
  • Presents a fast evaluation of code.


  • Might produce some false positives.
  • Can’t determine vulnerabilities ensuing from interactions between totally different sensible contracts (cross-contract calls).


MythX, a cloud-based static evaluation device, presents automated scanning for vulnerabilities in Ethereum and different EVM-based sensible contracts.


  • Gives a complete report on vulnerabilities.
  • Will be built-in with different instruments.
  • Straightforward to make use of.


  • Not an open-source device.
  • Can’t detect vulnerabilities involving interactions with different sensible contracts.
  • Cloud-based service, which some auditors and builders could choose to keep away from.

2. Dynamic Evaluation- includes executing sensible contracts with numerous inputs to determine runtime vulnerabilities and safety weaknesses. It assessments the contract’s behaviour throughout execution.

Goal: Reveals vulnerabilities that will solely manifest throughout runtime and helps assess precise contract behaviour.

Safety Testing Instruments: Mythril, Securify v2.0


Mythril is a static and dynamic evaluation device designed to detect vulnerabilities and weaknesses in Solidity code, together with these involving contract interactions.


  • Detects a variety of vulnerabilities, together with reentrancy assaults and integer underflow/overflow.
  • Combines each static and dynamic evaluation, making it extra versatile.
  • Person-friendly.


  • Slower evaluation, particularly with a excessive transaction rely.
  • Might generate false positives in some instances.

Securify v2.0

Securify 2.0, a safety scanner for Ethereum contracts, identifies numerous vulnerabilities, together with state shadowing, uninitialized storage, locked ether, unrestricted delegatecall, and reentrancy assaults.


  • Can discover as much as 37 totally different sensible contract vulnerabilities, together with uninitialized storage, locked ether, unrestricted delegated name, and so on.
  • Gives detailed studies.


  • Helps solely contracts with no imports(flat contracts).
  • Makes use of an previous model of Python.
  • Set up course of may be cumbersome.

3. Symbolic Execution- analyzes the sensible contract by creating symbolic representations of variables, inputs, and paths by means of the code. It explores numerous execution paths to uncover potential safety flaws.

Goal:  Environment friendly at exploring a number of code paths and discovering vulnerabilities that require advanced interactions.

Safety Testing Instruments: Manticore


Manticore is a symbolic execution device for Ethereum sensible contracts, Linux ELF binaries, and WASM modules. It explores attainable states of a program, generates inputs, and detects errors.


  • The sturdy symbolic execution engine allows navigation by means of numerous execution paths, program states, and sequences of transactions, making it exceptionally efficient in uncovering bugs.
  • Versatile in analyzing several types of software program corresponding to Ethereum sensible contracts, Linux ELF binaries, and WASM modules, broadening its scope for safety evaluation and bug detection.


  • Reminiscence-intensive and sluggish for giant or advanced software program.
  • Potential dependency conflicts with different CLI instruments.

4. Formal Verification- is a mathematical strategy to proving the correctness of sensible contracts primarily based on predefined specs. It makes use of logical reasoning to make sure the contract behaves as anticipated.

Goal: Rigorous mathematical proof of correctness, which may present excessive confidence within the safety of the contract.

Safety Testing Instruments: Solidity SMTChecker

Solidity SMTChecker

Solidity SMTChecker is a built-in formal verification module within the Solidity compiler. It makes use of SMT (Satisfiability Modulo Theories) and Horn fixing to verify for assertion failures inside sensible contracts.


  • Built-in with the Solidity compiler, requiring no advanced configurations.
  • Presents two mannequin checking engines, Bounded Mannequin Checker (BMC) and Constrained Horn Clauses (CHC).
  • Checks for numerous points, corresponding to arithmetic underflow and overflow, 


  • Restricted protection with BMC.
  • Excessive computational value when utilizing the CHC engine.
  • An experimental function.

5. Fuzz Testing- or fuzzing, includes injecting random or surprising information into sensible contracts to find vulnerabilities or weak factors that malicious actors may exploit.

Goal: Simulates real-world assault situations by testing contracts in opposition to numerous inputs.

Safety Testing Instruments: Echidna


Echidna is designed with a singular mix of fuzzing and property-based testing capabilities, and it’s constructed utilizing the Haskell programming language.


  • Echidna makes use of grammar-based fuzzing campaigns primarily based on a contract ABI and falsifies user-defined predicates or Solidity assert statements.
  • Echidna assessments sensible contracts primarily based on predefined invariants and generates random sequences of contract calls to check in opposition to these invariants.


  • Echidna may be sluggish in detecting vulnerabilities in massive contracts.
  • Testing contracts closely counting on exterior libraries could also be difficult.
  • Echidna’s help for the Vyper programming language is restricted, affecting its scope.

6. Invariant Testing- goals to make sure that particular circumstances or properties, corresponding to token balances or state consistency, stay legitimate and unchanged throughout contract execution. Invariants are checked constantly and assist forestall vulnerabilities.

Goal: focuses on verifying that sure invariants maintain all through the execution of a sensible contract.

Safety Testing Instruments: Foundry Invariant testing, Dapptools

Foundry Invariant Testing

Foundry is a high-speed sensible contract improvement device constructed utilizing the Rust programming language.


  • Foundry is thought for its velocity in sensible contract improvement.
  • It gives useful cheat codes and customizations for extra environment friendly testing, corresponding to rising the variety of fuzz take a look at runs.
  • Helps handler-based testing for invariant assessments that contain cross-contract interactions.


In some instances, customers could have to manually sure the vary of fuzzed enter numbers, as Foundry could not all the time select the proper enter values.


Dapptools is a collection of Ethereum-focused CLI instruments for constructing, testing, debugging, and deploying Solidity contracts.


  • Dapptools presents many testing choices, together with unit testing, fuzz testing, and invariant testing.
  • It permits customers to replay and debug failed assessments, offering perception into contract execution and reminiscence visualization.


  • Dapptools may be advanced to make use of, and debugging info could also be difficult to interpret.
  • It lacks neighborhood help, making problem-solving tougher.
  • Dapptools may be sluggish to run, and its documentation shouldn’t be complete, which may hinder consumer expertise.

7. Mutant Testing-  is a proactive strategy the place modifications are made to the code (mutants) to determine weaknesses within the contract’s logic. It helps to uncover vulnerabilities that conventional testing would possibly miss.

Goal: It includes introducing mutations (small variations) within the sensible contract’s code to verify in the event that they lead to vulnerabilities or points.

Safety Testing Instruments: SuMo


SuMo is a mutation testing device particularly designed for Solidity Sensible Contracts. It primarily operates within the NodeJS atmosphere and may be built-in into numerous improvement frameworks like Truffle, Hardhat, Brownie, and Foundry.


  • It’s versatile, providing help for Truffle, Hardhat, Brownie, and Foundry tasks. 
  • SuMo boasts a powerful array of 25 Solidity-specific mutation operators tailor-made to the intricacies of the Solidity programming language.
  • It may well generate a major quantity of mutated code for testing. Additionally, it introduces distinctive options, together with preflight, mutate and restore.


  • SuMo is meant to perform as a improvement dependency inside an npm undertaking, and world utilization shouldn’t be absolutely supported.
  • Could be slower in bigger tasks.

Combining these strategies can considerably cut back the danger of vulnerabilities and improve the reliability of blockchain functions.

Concluding Notice

In abstract, sensible contracts possess refined but vital points that make audits essential, typically requiring skilled professionals to unearth hidden flaws.

At QuillAudits, we’re dedicated to safeguarding your sensible contracts, guaranteeing they stand resilient in opposition to potential threats.

Join with our professional auditors right now and expertise the boldness of a safe blockchain future!



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