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.
- Detects vulnerable Solidity code with low false positives
- 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) enables simple, high-precision analyses
- Correctly parses 99.9% of all public Solidity code
- Average execution time of less than 1 second per contract
Run Slither on a Truffle/Embark/Dapp/Etherlime application:
slither .Run Slither on a single file:
slither tests/uninitialized.solFor additional configuration, see the usage documentation.
Use solc-select if your contracts require older versions of solc.
| Num | Detector | What it Detects | Impact | Confidence |
|---|---|---|---|---|
| 1 | name-reused |
Contract's name reused | High | High |
| 2 | rtlo |
Right-To-Left-Override control character is used | High | High |
| 3 | shadowing-state |
State variables shadowing | High | High |
| 4 | suicidal |
Functions allowing anyone to destruct the contract | High | High |
| 5 | uninitialized-state |
Uninitialized state variables | High | High |
| 6 | uninitialized-storage |
Uninitialized storage variables | High | High |
| 7 | arbitrary-send |
Functions that send ether to arbitrary destinations | High | Medium |
| 8 | controlled-delegatecall |
Controlled delegatecall destination | High | Medium |
| 9 | reentrancy-eth |
Reentrancy vulnerabilities (theft of ethers) | High | Medium |
| 10 | erc20-interface |
Incorrect ERC20 interfaces | Medium | High |
| 11 | erc721-interface |
Incorrect ERC721 interfaces | Medium | High |
| 12 | incorrect-equality |
Dangerous strict equalities | Medium | High |
| 13 | locked-ether |
Contracts that lock ether | Medium | High |
| 14 | shadowing-abstract |
State variables shadowing from abstract contracts | Medium | High |
| 15 | tautology |
Tautology or contradiction | Medium | High |
| 16 | boolean-cst |
Misuse of Boolean constant | Medium | Medium |
| 17 | constant-function-asm |
Constant functions using assembly code | Medium | Medium |
| 18 | constant-function-state |
Constant functions changing the state | Medium | Medium |
| 19 | divide-before-multiply |
Imprecise arithmetic operations order | Medium | Medium |
| 20 | reentrancy-no-eth |
Reentrancy vulnerabilities (no theft of ethers) | Medium | Medium |
| 21 | tx-origin |
Dangerous usage of tx.origin |
Medium | Medium |
| 22 | unchecked-lowlevel |
Unchecked low-level calls | Medium | Medium |
| 23 | unchecked-send |
Unchecked send | Medium | Medium |
| 24 | uninitialized-local |
Uninitialized local variables | Medium | Medium |
| 25 | unused-return |
Unused return values | Medium | Medium |
| 26 | shadowing-builtin |
Built-in symbol shadowing | Low | High |
| 27 | shadowing-local |
Local variables shadowing | Low | High |
| 28 | void-cst |
Constructor called not implemented | Low | High |
| 29 | calls-loop |
Multiple calls in a loop | Low | Medium |
| 30 | reentrancy-benign |
Benign reentrancy vulnerabilities | Low | Medium |
| 31 | reentrancy-events |
Reentrancy vulnerabilities leading to out-of-order Events | Low | Medium |
| 32 | timestamp |
Dangerous usage of block.timestamp |
Low | Medium |
| 33 | assembly |
Assembly usage | Informational | High |
| 34 | boolean-equal |
Comparison to boolean constant | Informational | High |
| 35 | deprecated-standards |
Deprecated Solidity Standards | Informational | High |
| 36 | erc20-indexed |
Un-indexed ERC20 event parameters | Informational | High |
| 37 | low-level-calls |
Low level calls | Informational | High |
| 38 | naming-convention |
Conformance to Solidity naming conventions | Informational | High |
| 39 | pragma |
If different pragma directives are used | Informational | High |
| 40 | solc-version |
Incorrect Solidity version | Informational | High |
| 41 | unused-state |
Unused state variables | Informational | High |
| 42 | reentrancy-unlimited-gas |
Reentrancy vulnerabilities through send and transfer | Informational | Medium |
| 43 | too-many-digits |
Conformance to numeric notation best practices | Informational | Medium |
| 44 | constable-states |
State variables that could be declared constant | Optimization | High |
| 45 | external-function |
Public function that could be declared as external | Optimization | High |
See the Detectors Documentation for more information. By default, all the detectors are run.
Check out Crytic to get access to additional Slither's detectors and GitHub integration.
human-summary: Print a human-readable summary of the contractsinheritance-graph: Export the inheritance graph of each contract to a dot filecontract-summary: Print a summary of the contracts
call-graph: Export the call-graph of the contracts to a dot filecfg: Export the CFG of each functionsfunction-summary: Print a summary of the functionsvars-and-auth: Print the state variables written and the authorization of the functions
To run a printer, use --print and a comma-separated list of printers.
See the Printer documentation for the complete lists.
slither-check-upgradeability: Reviewdelegatecall-based upgradeabilityslither-prop: Automatic unit tests and properties generationslither-flat: Flatten a codebaseslither-check-erc: Check the ERC's conformanceslither-format: Automatic patches generation
See the Tool documentation for additional tools.
Contact us to get help on building custom tools.
Slither requires Python 3.6+ and solc, the Solidity compiler.
pip3 install slither-analyzergit clone https://github.com/crytic/slither.git && cd slither
python3 setup.py installWe recommend using an Python virtual environment, as detailed in the Developer Installation Instructions, if you prefer to install Slither via git.
Use the 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.
docker pull trailofbits/eth-security-toolboxTo share a directory in the container:
docker run -it -v /home/share:/share trailofbits/eth-security-toolboxFeel free to stop by our Slack channel (#ethereum) for help using or extending Slither.
-
The Printer documentation describes the information Slither is capable of visualizing for each contract.
-
The Detector documentation describes how to write a new vulnerability analyses.
-
The API documentation describes the methods and objects available for custom analyses.
-
The SlithIR documentation describes the SlithIR intermediate representation.
Slither is licensed and distributed under the AGPLv3 license. Contact us if you're looking for an exception to the terms.
- Slither: A Static Analysis Framework For Smart Contracts, Josselin Feist, Gustavo Grieco, Alex Groce - WETSEB '19
- 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, William Zhang, Sebastian Banescu, Leodardo Pasos, Steven Stewart, Vijay Ganesh - ISSRE 2019
- ETHPLOIT: From Fuzzing to Efficient Exploit Generation against Smart Contracts, Qingzhao Zhang, Yizhuo Wang, Juanru Li, Siqi Ma - SANER 20
- Verification of Ethereum Smart Contracts: A Model Checking Approach, Tam Bang, Hoang H Nguyen, Dung Nguyen, Toan Trieu, Tho Quan - IJMLC 20
- Smart Contract Repair, Xiao Liang Yu, Omar Al-Bataineh, David Lo, Abhik Roychoudhury - TOSEM 20
If you are using Slither on an academic work, consider applying to the Crytic $10k Research Prize.