slither-analyzer 0.7.1

Slither is a Solidity static analysis framework written in Python 3.

# Slither, the Solidity source analyzer <img src=”./logo.png” alt=”Logo” width=”500”/>

[](https://github.com/crytic/slither/actions?query=workflow%3ACI) [](https://empireslacking.herokuapp.com) [](https://badge.fury.io/py/slither-analyzer)

Slither is a Solidity static analysis framework written in Python 3. It runs a suite of vulnerability detectors, prints visual information about contract details, and provides an API to easily write custom analyses. Slither enables developers to find vulnerabilities, enhance their code comprehension, and quickly prototype custom analyses.

• [Features](#features)

• [Bugs and Optimizations Detection](#bugs-and-optimizations-detection)

• [Printers](#printers)

• [Tools](#tools)

• [How to Install](#how-to-install)

• [Getting Help](#getting-help)

• [Publications](#publications)

## Features

• Detects vulnerable Solidity code with low false positives (see the list of [trophies](./trophies.md))

• Identifies where the error condition occurs in the source code

• Easily integrates into continuous integration and Truffle builds

• Built-in ‘printers’ quickly report crucial contract information

• Detector API to write custom analyses in Python

• Ability to analyze contracts written with Solidity >= 0.4

• Intermediate representation ([SlithIR](https://github.com/trailofbits/slither/wiki/SlithIR)) enables simple, high-precision analyses

• Correctly parses 99.9% of all public Solidity code

• Average execution time of less than 1 second per contract

## Bugs and Optimizations Detection

Run Slither on a Truffle/Embark/Dapp/Etherlime/Hardhat application: `bash slither . `

Run Slither on a single file: `bash slither tests/uninitialized.sol `

For additional configuration, see the [usage](https://github.com/trailofbits/slither/wiki/Usage) documentation.

Use [solc-select](https://github.com/crytic/solc-select) if your contracts require older versions of solc.

### Detectors

Num | Detector | What it Detects | Impact | Confidence — | — | — | — | — 1 | abiencoderv2-array | [Storage abiencoderv2 array](https://github.com/crytic/slither/wiki/Detector-Documentation#storage-abiencoderv2-array) | High | High 2 | array-by-reference | [Modifying storage array by value](https://github.com/crytic/slither/wiki/Detector-Documentation#modifying-storage-array-by-value) | High | High 3 | incorrect-shift | [The order of parameters in a shift instruction is incorrect.](https://github.com/crytic/slither/wiki/Detector-Documentation#shift-parameter-mixup) | High | High 4 | multiple-constructors | [Multiple constructor schemes](https://github.com/crytic/slither/wiki/Detector-Documentation#multiple-constructor-schemes) | High | High 5 | name-reused | [Contract’s name reused](https://github.com/crytic/slither/wiki/Detector-Documentation#name-reused) | High | High 6 | public-mappings-nested | [Public mappings with nested variables](https://github.com/crytic/slither/wiki/Detector-Documentation#public-mappings-with-nested-variables) | High | High 7 | rtlo | [Right-To-Left-Override control character is used](https://github.com/crytic/slither/wiki/Detector-Documentation#right-to-left-override-character) | High | High 8 | shadowing-state | [State variables shadowing](https://github.com/crytic/slither/wiki/Detector-Documentation#state-variable-shadowing) | High | High 9 | suicidal | [Functions allowing anyone to destruct the contract](https://github.com/crytic/slither/wiki/Detector-Documentation#suicidal) | High | High 10 | uninitialized-state | [Uninitialized state variables](https://github.com/crytic/slither/wiki/Detector-Documentation#uninitialized-state-variables) | High | High 11 | uninitialized-storage | [Uninitialized storage variables](https://github.com/crytic/slither/wiki/Detector-Documentation#uninitialized-storage-variables) | High | High 12 | unprotected-upgrade | [Unprotected upgradeable contract](https://github.com/crytic/slither/wiki/Detector-Documentation#unprotected-upgradeable-contract) | High | High 13 | arbitrary-send | [Functions that send Ether to arbitrary destinations](https://github.com/crytic/slither/wiki/Detector-Documentation#functions-that-send-ether-to-arbitrary-destinations) | High | Medium 14 | controlled-array-length | [Tainted array length assignment](https://github.com/crytic/slither/wiki/Detector-Documentation#array-length-assignment) | High | Medium 15 | controlled-delegatecall | [Controlled delegatecall destination](https://github.com/crytic/slither/wiki/Detector-Documentation#controlled-delegatecall) | High | Medium 16 | reentrancy-eth | [Reentrancy vulnerabilities (theft of ethers)](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities) | High | Medium 17 | storage-array | [Signed storage integer array compiler bug](https://github.com/crytic/slither/wiki/Detector-Documentation#storage-signed-integer-array) | High | Medium 18 | weak-prng | [Weak PRNG](https://github.com/crytic/slither/wiki/Detector-Documentation#weak-PRNG) | High | Medium 19 | enum-conversion | [Detect dangerous enum conversion](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-enum-conversion) | Medium | High 20 | erc20-interface | [Incorrect ERC20 interfaces](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-erc20-interface) | Medium | High 21 | erc721-interface | [Incorrect ERC721 interfaces](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-erc721-interface) | Medium | High 22 | incorrect-equality | [Dangerous strict equalities](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-strict-equalities) | Medium | High 23 | locked-ether | [Contracts that lock ether](https://github.com/crytic/slither/wiki/Detector-Documentation#contracts-that-lock-ether) | Medium | High 24 | mapping-deletion | [Deletion on mapping containing a structure](https://github.com/crytic/slither/wiki/Detector-Documentation#deletion-on-mapping-containing-a-structure) | Medium | High 25 | shadowing-abstract | [State variables shadowing from abstract contracts](https://github.com/crytic/slither/wiki/Detector-Documentation#state-variable-shadowing-from-abstract-contracts) | Medium | High 26 | tautology | [Tautology or contradiction](https://github.com/crytic/slither/wiki/Detector-Documentation#tautology-or-contradiction) | Medium | High 27 | boolean-cst | [Misuse of Boolean constant](https://github.com/crytic/slither/wiki/Detector-Documentation#misuse-of-a-boolean-constant) | Medium | Medium 28 | constant-function-asm | [Constant functions using assembly code](https://github.com/crytic/slither/wiki/Detector-Documentation#constant-functions-using-assembly-code) | Medium | Medium 29 | constant-function-state | [Constant functions changing the state](https://github.com/crytic/slither/wiki/Detector-Documentation#constant-functions-changing-the-state) | Medium | Medium 30 | divide-before-multiply | [Imprecise arithmetic operations order](https://github.com/crytic/slither/wiki/Detector-Documentation#divide-before-multiply) | Medium | Medium 31 | reentrancy-no-eth | [Reentrancy vulnerabilities (no theft of ethers)](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-1) | Medium | Medium 32 | reused-constructor | [Reused base constructor](https://github.com/crytic/slither/wiki/Detector-Documentation#reused-base-constructors) | Medium | Medium 33 | tx-origin | [Dangerous usage of tx.origin](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-usage-of-txorigin) | Medium | Medium 34 | unchecked-lowlevel | [Unchecked low-level calls](https://github.com/crytic/slither/wiki/Detector-Documentation#unchecked-low-level-calls) | Medium | Medium 35 | unchecked-send | [Unchecked send](https://github.com/crytic/slither/wiki/Detector-Documentation#unchecked-send) | Medium | Medium 36 | uninitialized-local | [Uninitialized local variables](https://github.com/crytic/slither/wiki/Detector-Documentation#uninitialized-local-variables) | Medium | Medium 37 | unused-return | [Unused return values](https://github.com/crytic/slither/wiki/Detector-Documentation#unused-return) | Medium | Medium 38 | incorrect-modifier | [Modifiers that can return the default value](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-modifier) | Low | High 39 | shadowing-builtin | [Built-in symbol shadowing](https://github.com/crytic/slither/wiki/Detector-Documentation#builtin-symbol-shadowing) | Low | High 40 | shadowing-local | [Local variables shadowing](https://github.com/crytic/slither/wiki/Detector-Documentation#local-variable-shadowing) | Low | High 41 | uninitialized-fptr-cst | [Uninitialized function pointer calls in constructors](https://github.com/crytic/slither/wiki/Detector-Documentation#uninitialized-function-pointers-in-constructors) | Low | High 42 | variable-scope | [Local variables used prior their declaration](https://github.com/crytic/slither/wiki/Detector-Documentation#pre-declaration-usage-of-local-variables) | Low | High 43 | void-cst | [Constructor called not implemented](https://github.com/crytic/slither/wiki/Detector-Documentation#void-constructor) | Low | High 44 | calls-loop | [Multiple calls in a loop](https://github.com/crytic/slither/wiki/Detector-Documentation/#calls-inside-a-loop) | Low | Medium 45 | events-access | [Missing Events Access Control](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-events-access-control) | Low | Medium 46 | events-maths | [Missing Events Arithmetic](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-events-arithmetic) | Low | Medium 47 | incorrect-unary | [Dangerous unary expressions](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-unary-expressions) | Low | Medium 48 | missing-zero-check | [Missing Zero Address Validation](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-zero-address-validation) | Low | Medium 49 | reentrancy-benign | [Benign reentrancy vulnerabilities](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-2) | Low | Medium 50 | reentrancy-events | [Reentrancy vulnerabilities leading to out-of-order Events](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-3) | Low | Medium 51 | timestamp | [Dangerous usage of block.timestamp](https://github.com/crytic/slither/wiki/Detector-Documentation#block-timestamp) | Low | Medium 52 | assembly | [Assembly usage](https://github.com/crytic/slither/wiki/Detector-Documentation#assembly-usage) | Informational | High 53 | boolean-equal | [Comparison to boolean constant](https://github.com/crytic/slither/wiki/Detector-Documentation#boolean-equality) | Informational | High 54 | deprecated-standards | [Deprecated Solidity Standards](https://github.com/crytic/slither/wiki/Detector-Documentation#deprecated-standards) | Informational | High 55 | erc20-indexed | [Un-indexed ERC20 event parameters](https://github.com/crytic/slither/wiki/Detector-Documentation#unindexed-erc20-event-parameters) | Informational | High 56 | function-init-state | [Function initializing state variables](https://github.com/crytic/slither/wiki/Detector-Documentation#function-initializing-state-variables) | Informational | High 57 | low-level-calls | [Low level calls](https://github.com/crytic/slither/wiki/Detector-Documentation#low-level-calls) | Informational | High 58 | missing-inheritance | [Missing inheritance](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-inheritance) | Informational | High 59 | naming-convention | [Conformity to Solidity naming conventions](https://github.com/crytic/slither/wiki/Detector-Documentation#conformance-to-solidity-naming-conventions) | Informational | High 60 | pragma | [If different pragma directives are used](https://github.com/crytic/slither/wiki/Detector-Documentation#different-pragma-directives-are-used) | Informational | High 61 | redundant-statements | [Redundant statements](https://github.com/crytic/slither/wiki/Detector-Documentation#redundant-statements) | Informational | High 62 | solc-version | [Incorrect Solidity version](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-versions-of-solidity) | Informational | High 63 | unimplemented-functions | [Unimplemented functions](https://github.com/crytic/slither/wiki/Detector-Documentation#unimplemented-functions) | Informational | High 64 | unused-state | [Unused state variables](https://github.com/crytic/slither/wiki/Detector-Documentation#unused-state-variables) | Informational | High 65 | assert-state-change | [Assert state change](https://github.com/crytic/slither/wiki/Detector-Documentation#assert-state-change) | Informational | High 66 | costly-loop | [Costly operations in a loop](https://github.com/crytic/slither/wiki/Detector-Documentation#costly-operations-inside-a-loop) | Informational | Medium 67 | reentrancy-unlimited-gas | [Reentrancy vulnerabilities through send and transfer](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-4) | Informational | Medium 68 | similar-names | [Variable names are too similar](https://github.com/crytic/slither/wiki/Detector-Documentation#variable-names-are-too-similar) | Informational | Medium 69 | too-many-digits | [Conformance to numeric notation best practices](https://github.com/crytic/slither/wiki/Detector-Documentation#too-many-digits) | Informational | Medium 70 | constable-states | [State variables that could be declared constant](https://github.com/crytic/slither/wiki/Detector-Documentation#state-variables-that-could-be-declared-constant) | Optimization | High 71 | external-function | [Public function that could be declared external](https://github.com/crytic/slither/wiki/Detector-Documentation#public-function-that-could-be-declared-external) | Optimization | High

See the [Detectors Documentation](https://github.com/crytic/slither/wiki/Detector-Documentation) for more information. By default, all the detectors are run.

Check out [Crytic](https://crytic.io/) to get access to additional Slither’s detectors and GitHub integration.

## Printers

### Quick Review Printers - human-summary: [Print a human-readable summary of the contracts](https://github.com/trailofbits/slither/wiki/Printer-documentation#human-summary) - inheritance-graph: [Export the inheritance graph of each contract to a dot file](https://github.com/trailofbits/slither/wiki/Printer-documentation#inheritance-graph) - contract-summary: [Print a summary of the contracts](https://github.com/trailofbits/slither/wiki/Printer-documentation#contract-summary)

### In-Depth Review Printers - call-graph: [Export the call-graph of the contracts to a dot file](https://github.com/trailofbits/slither/wiki/Printer-documentation#call-graph) - cfg: [Export the CFG of each functions](https://github.com/trailofbits/slither/wiki/Printer-documentation#cfg) - function-summary: [Print a summary of the functions](https://github.com/trailofbits/slither/wiki/Printer-documentation#function-summary) - vars-and-auth: [Print the state variables written and the authorization of the functions](https://github.com/crytic/slither/wiki/Printer-documentation#variables-written-and-authorization)

To run a printer, use –print and a comma-separated list of printers.

See the [Printer documentation](https://github.com/crytic/slither/wiki/Printer-documentation) for the complete lists.

## Tools

• slither-check-upgradeability: [Review delegatecall-based upgradeability](https://github.com/crytic/slither/wiki/Upgradeability-Checks)

• slither-prop: [Automatic unit test and property generation](https://github.com/crytic/slither/wiki/Property-generation)

• slither-flat: [Flatten a codebase](https://github.com/crytic/slither/wiki/Contract-Flattening)

• slither-check-erc: [Check the ERC’s conformance](https://github.com/crytic/slither/wiki/ERC-Conformance)

• slither-format: [Automatic patches generation](https://github.com/crytic/slither/wiki/Slither-format)

See the [Tool documentation](https://github.com/crytic/slither/wiki/Tool-Documentation) for additional tools.

[Contact us](https://www.trailofbits.com/contact/) to get help on building custom tools.

## How to install

Slither requires Python 3.6+ and [solc](https://github.com/ethereum/solidity/), the Solidity compiler.

### Using Pip

`bash pip3 install slither-analyzer `

### Using Git

`bash git clone https://github.com/crytic/slither.git && cd slither python3 setup.py install `

We recommend using an Python virtual environment, as detailed in the [Developer Installation Instructions](https://github.com/trailofbits/slither/wiki/Developer-installation), if you prefer to install Slither via git.

### Using Docker

Use the [eth-security-toolbox](https://github.com/trailofbits/eth-security-toolbox/) docker image. It includes all of our security tools and every major version of Solidity in a single image. /home/share will be mounted to /share in the container.

`bash docker pull trailofbits/eth-security-toolbox `

To share a directory in the container:

`bash docker run -it -v /home/share:/share trailofbits/eth-security-toolbox `

## Getting Help

Feel free to stop by our [Slack channel](https://empireslacking.herokuapp.com) (#ethereum) for help using or extending Slither.

• The [Printer documentation](https://github.com/trailofbits/slither/wiki/Printer-documentation) describes the information Slither is capable of visualizing for each contract.

• The [Detector documentation](https://github.com/trailofbits/slither/wiki/Adding-a-new-detector) describes how to write a new vulnerability analyses.

• The [API documentation](https://github.com/trailofbits/slither/wiki/API-examples) describes the methods and objects available for custom analyses.

• The [SlithIR documentation](https://github.com/trailofbits/slither/wiki/SlithIR) describes the SlithIR intermediate representation.

## License

Slither is licensed and distributed under the AGPLv3 license. [Contact us](mailto:[e-mail]) if you’re looking for an exception to the terms.

## Publications

### Trail of Bits publication - [Slither: A Static Analysis Framework For Smart Contracts](https://arxiv.org/abs/1908.09878), Josselin Feist, Gustavo Grieco, Alex Groce - WETSEB ‘19

### External publications - [ReJection: A AST-Based Reentrancy Vulnerability Detection Method](https://www.researchgate.net/publication/339354823_ReJection_A_AST-Based_Reentrancy_Vulnerability_Detection_Method), Rui Ma, Zefeng Jian, Guangyuan Chen, Ke Ma, Yujia Chen - CTCIS 19 - [MPro: Combining Static and Symbolic Analysis forScalable Testing of Smart Contract](https://arxiv.org/pdf/1911.00570.pdf), William Zhang, Sebastian Banescu, Leodardo Pasos, Steven Stewart, Vijay Ganesh - ISSRE 2019 - [ETHPLOIT: From Fuzzing to Efficient Exploit Generation against Smart Contracts](https://wcventure.github.io/FuzzingPaper/Paper/SANER20_ETHPLOIT.pdf), Qingzhao Zhang, Yizhuo Wang, Juanru Li, Siqi Ma - SANER 20 - [Verification of Ethereum Smart Contracts: A Model Checking Approach](http://www.ijmlc.org/vol10/977-AM0059.pdf), Tam Bang, Hoang H Nguyen, Dung Nguyen, Toan Trieu, Tho Quan - IJMLC 20 - [Smart Contract Repair](https://arxiv.org/pdf/1912.05823.pdf), Xiao Liang Yu, Omar Al-Bataineh, David Lo, Abhik Roychoudhury - TOSEM 20 - [Demystifying Loops in Smart Contracts](https://www.microsoft.com/en-us/research/uploads/prod/2020/08/loops_solidity__camera_ready-5f3fec3f15c69.pdf), Ben Mariano, Yanju Chen, Yu Feng, Shuvendu Lahiri, Isil Dillig - ASE 20

If you are using Slither on an academic work, consider applying to the [Crytic $10k Research Prize](https://blog.trailofbits.com/2019/11/13/announcing-the-crytic-10k-research-prize/).