Slither, the Solidity source 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

• Detects vulnerable Solidity code with low false positives
• Identifies where the error condition occurs in the source code
• Easy integration 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

Changelog v0.6  2019-02-15

This release adds 3 new detectors, 5 new printers, improves the overall usability of Slither, and introduces a new tool: slither-check-upgradability to help to review upradable contracts. A large effort has been made to improve our user documentation and developper documentation. This release brings also several bugfixes, API enhancements and lowers the rate of false positives for several detectors.

Added

• Detectors:
  • erc20-interface: Incorrect ERC20 interfaces
  • erc20-indexed: Un-indexed ERC20 event parameters
  • deprecated-standards: Deprecated Solidity Standards
• Printers:
  • data-dependency: Print the data dependencies of the variables
  • function-id: Print the keccack256 signature of the functions
  • modifiers: Print the modifiers called by each function
  • require: Print the require and assert calls of each function
  • variable-order: Print the storage order of the state variables
• Command line usage:
  • --ignore-truffle-compile: do not run truffle compile
  • --disable-color: disable output colorization
  • --triage-mode: run slither in its triage mode. For every finding, Slither will ask if the result should be shown for the next run.
  • --filter-paths: exclude all the results that are only related to the given paths.
  • Configuration file: Slither options can be configured through a JSON file. See the documentation
• slither-check-upgradability: Utility to help reviewing upgradable contracts
• Dependency: require pysha3>=1.0.2

Changed:

• Reduce the false alarms rates of:
  • Unused variables: consider expression oustide of the functions’ scope #167
  • Reentrancy: check if a call to this is reentrancy-safe + don’t consider view/pure calls for Solidity >= 0.5 #127 #126
  • Locked ether: follow libraries calls #163
• Improve Truffle integration: Slither will automatically switch to the truffle version provided in package.json (#154)
• Improve SSA conversion: Use of an interprocedural sensitive analysis (follow parameters) (#156 (comment))
• Improve data dependency: Compute a fix-point on function context (#171)
• Improve inheritance printer output (#162, #166)
• Add support of staticall (#152)

Fixed

• Several minors bugs, including:
  • Incorrect SSA conversion on Return (59af388)
  • is_storage property on StateVariableIR/LocalVariableIR (59af388)
  • Crash when two variables have the same name #151
  • Incorrect location for LocalVariableIR (#143)
  • Add constant folding visitor to avoid crash on expression-based length (#144)

Install

Slither requires Python 3.6+ and solc, the Solidity compiler.

Using Pip

$ pip install slither-analyzer

Using Git

Use

Run Slither on a Truffle application:

slither .

Run Slither on a single file:

$ slither tests/uninitialized.sol 
[..]
INFO:Detectors:
Uninitialized.destination (tests/uninitialized.sol#5) is never initialized. It is used in:
	- transfer (tests/uninitialized.sol#7-9)
Reference: https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#uninitialized-state-variables
[..]

Slither can be run on:

• A .sol file
• A Truffle directory
• A directory containing *.sol files (all the *.sol files will be analyzed)
• A glob (be sure to quote the argument when using a glob)

Configuration

• --solc SOLC: Path to solc (default ‘solc’)
• --solc-args SOLC_ARGS: Add custom solc arguments. SOLC_ARGS can contain multiple arguments
• --disable-solc-warnings: Do not print solc warnings
• --solc-ast: Use the solc AST file as input (solc file.sol --ast-json > file.ast.json)
• --json FILE: Export results as JSON

Detectors

By default, all the detectors are run.

Printers

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

Tutorial

Copyright (C) 2018 trailofbits