slither-analyzer 0.8.1

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 | unchecked-transfer | [Unchecked tokens transfer](https://github.com/crytic/slither/wiki/Detector-Documentation#unchecked-transfer) | High | Medium 19 | weak-prng | [Weak PRNG](https://github.com/crytic/slither/wiki/Detector-Documentation#weak-PRNG) | High | Medium 20 | enum-conversion | [Detect dangerous enum conversion](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-enum-conversion) | Medium | High 21 | erc20-interface | [Incorrect ERC20 interfaces](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-erc20-interface) | Medium | High 22 | erc721-interface | [Incorrect ERC721 interfaces](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-erc721-interface) | Medium | High 23 | incorrect-equality | [Dangerous strict equalities](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-strict-equalities) | Medium | High 24 | locked-ether | [Contracts that lock ether](https://github.com/crytic/slither/wiki/Detector-Documentation#contracts-that-lock-ether) | Medium | High 25 | mapping-deletion | [Deletion on mapping containing a structure](https://github.com/crytic/slither/wiki/Detector-Documentation#deletion-on-mapping-containing-a-structure) | Medium | High 26 | shadowing-abstract | [State variables shadowing from abstract contracts](https://github.com/crytic/slither/wiki/Detector-Documentation#state-variable-shadowing-from-abstract-contracts) | Medium | High 27 | tautology | [Tautology or contradiction](https://github.com/crytic/slither/wiki/Detector-Documentation#tautology-or-contradiction) | Medium | High 28 | write-after-write | [Unused write](https://github.com/crytic/slither/wiki/Detector-Documentation#write-after-write) | Medium | High 29 | boolean-cst | [Misuse of Boolean constant](https://github.com/crytic/slither/wiki/Detector-Documentation#misuse-of-a-boolean-constant) | Medium | Medium 30 | constant-function-asm | [Constant functions using assembly code](https://github.com/crytic/slither/wiki/Detector-Documentation#constant-functions-using-assembly-code) | Medium | Medium 31 | constant-function-state | [Constant functions changing the state](https://github.com/crytic/slither/wiki/Detector-Documentation#constant-functions-changing-the-state) | Medium | Medium 32 | divide-before-multiply | [Imprecise arithmetic operations order](https://github.com/crytic/slither/wiki/Detector-Documentation#divide-before-multiply) | Medium | Medium 33 | reentrancy-no-eth | [Reentrancy vulnerabilities (no theft of ethers)](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-1) | Medium | Medium 34 | reused-constructor | [Reused base constructor](https://github.com/crytic/slither/wiki/Detector-Documentation#reused-base-constructors) | Medium | Medium 35 | tx-origin | [Dangerous usage of tx.origin](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-usage-of-txorigin) | Medium | Medium 36 | unchecked-lowlevel | [Unchecked low-level calls](https://github.com/crytic/slither/wiki/Detector-Documentation#unchecked-low-level-calls) | Medium | Medium 37 | unchecked-send | [Unchecked send](https://github.com/crytic/slither/wiki/Detector-Documentation#unchecked-send) | Medium | Medium 38 | uninitialized-local | [Uninitialized local variables](https://github.com/crytic/slither/wiki/Detector-Documentation#uninitialized-local-variables) | Medium | Medium 39 | unused-return | [Unused return values](https://github.com/crytic/slither/wiki/Detector-Documentation#unused-return) | Medium | Medium 40 | incorrect-modifier | [Modifiers that can return the default value](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-modifier) | Low | High 41 | shadowing-builtin | [Built-in symbol shadowing](https://github.com/crytic/slither/wiki/Detector-Documentation#builtin-symbol-shadowing) | Low | High 42 | shadowing-local | [Local variables shadowing](https://github.com/crytic/slither/wiki/Detector-Documentation#local-variable-shadowing) | Low | High 43 | uninitialized-fptr-cst | [Uninitialized function pointer calls in constructors](https://github.com/crytic/slither/wiki/Detector-Documentation#uninitialized-function-pointers-in-constructors) | Low | High 44 | variable-scope | [Local variables used prior their declaration](https://github.com/crytic/slither/wiki/Detector-Documentation#pre-declaration-usage-of-local-variables) | Low | High 45 | void-cst | [Constructor called not implemented](https://github.com/crytic/slither/wiki/Detector-Documentation#void-constructor) | Low | High 46 | calls-loop | [Multiple calls in a loop](https://github.com/crytic/slither/wiki/Detector-Documentation/#calls-inside-a-loop) | Low | Medium 47 | events-access | [Missing Events Access Control](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-events-access-control) | Low | Medium 48 | events-maths | [Missing Events Arithmetic](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-events-arithmetic) | Low | Medium 49 | incorrect-unary | [Dangerous unary expressions](https://github.com/crytic/slither/wiki/Detector-Documentation#dangerous-unary-expressions) | Low | Medium 50 | missing-zero-check | [Missing Zero Address Validation](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-zero-address-validation) | Low | Medium 51 | reentrancy-benign | [Benign reentrancy vulnerabilities](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-2) | Low | Medium 52 | reentrancy-events | [Reentrancy vulnerabilities leading to out-of-order Events](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-3) | Low | Medium 53 | timestamp | [Dangerous usage of block.timestamp](https://github.com/crytic/slither/wiki/Detector-Documentation#block-timestamp) | Low | Medium 54 | assembly | [Assembly usage](https://github.com/crytic/slither/wiki/Detector-Documentation#assembly-usage) | Informational | High 55 | assert-state-change | [Assert state change](https://github.com/crytic/slither/wiki/Detector-Documentation#assert-state-change) | Informational | High 56 | boolean-equal | [Comparison to boolean constant](https://github.com/crytic/slither/wiki/Detector-Documentation#boolean-equality) | Informational | High 57 | deprecated-standards | [Deprecated Solidity Standards](https://github.com/crytic/slither/wiki/Detector-Documentation#deprecated-standards) | Informational | High 58 | erc20-indexed | [Un-indexed ERC20 event parameters](https://github.com/crytic/slither/wiki/Detector-Documentation#unindexed-erc20-event-parameters) | Informational | High 59 | function-init-state | [Function initializing state variables](https://github.com/crytic/slither/wiki/Detector-Documentation#function-initializing-state-variables) | Informational | High 60 | low-level-calls | [Low level calls](https://github.com/crytic/slither/wiki/Detector-Documentation#low-level-calls) | Informational | High 61 | missing-inheritance | [Missing inheritance](https://github.com/crytic/slither/wiki/Detector-Documentation#missing-inheritance) | Informational | High 62 | naming-convention | [Conformity to Solidity naming conventions](https://github.com/crytic/slither/wiki/Detector-Documentation#conformance-to-solidity-naming-conventions) | Informational | High 63 | pragma | [If different pragma directives are used](https://github.com/crytic/slither/wiki/Detector-Documentation#different-pragma-directives-are-used) | Informational | High 64 | redundant-statements | [Redundant statements](https://github.com/crytic/slither/wiki/Detector-Documentation#redundant-statements) | Informational | High 65 | solc-version | [Incorrect Solidity version](https://github.com/crytic/slither/wiki/Detector-Documentation#incorrect-versions-of-solidity) | Informational | High 66 | unimplemented-functions | [Unimplemented functions](https://github.com/crytic/slither/wiki/Detector-Documentation#unimplemented-functions) | Informational | High 67 | unused-state | [Unused state variables](https://github.com/crytic/slither/wiki/Detector-Documentation#unused-state-variables) | Informational | High 68 | costly-loop | [Costly operations in a loop](https://github.com/crytic/slither/wiki/Detector-Documentation#costly-operations-inside-a-loop) | Informational | Medium 69 | dead-code | [Functions that are not used](https://github.com/crytic/slither/wiki/Detector-Documentation#dead-code) | Informational | Medium 70 | reentrancy-unlimited-gas | [Reentrancy vulnerabilities through send and transfer](https://github.com/crytic/slither/wiki/Detector-Documentation#reentrancy-vulnerabilities-4) | Informational | Medium 71 | similar-names | [Variable names are too similar](https://github.com/crytic/slither/wiki/Detector-Documentation#variable-names-are-too-similar) | Informational | Medium 72 | too-many-digits | [Conformance to numeric notation best practices](https://github.com/crytic/slither/wiki/Detector-Documentation#too-many-digits) | Informational | Medium 73 | 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 74 | 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

For more information, see - The [Detector Documentation](https://github.com/crytic/slither/wiki/Detector-Documentation) for details on each detector - The [Detection Selection](https://github.com/crytic/slither/wiki/Usage#detector-selection) to run only selected detectors. By default, all the detectors are run. - The [Triage Mode](https://github.com/crytic/slither/wiki/Usage#triage-mode) to filter individual results

## 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 patch 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 - [Trace-Based Dynamic Gas Estimation of Loops in Smart Contracts](https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9268144), Chunmiao Li, Shijie Nie, Yang Cao, Yijun Yu, Zhenjiang Hu - IEEE Open J. Comput. Soc. 1 (2020)

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/).