slither: Static Analyzer for Solidity

by ddos ·

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.

 

slither

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

Install

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

Using Pip

$ pip install slither-analyzer

Using Git

$ git clone https://github.com/trailofbits/slither.git && cd slither
$ python setup.py install

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.

Num Detector What it Detects Impact Confidence
1 suicidal Functions allowing anyone to destruct the contract High High
2 uninitialized-local Uninitialized local variables High High
3 uninitialized-state Uninitialized state variables High High
4 uninitialized-storage Uninitialized storage variables High High
5 arbitrary-send Functions that send ether to arbitrary destinations High Medium
6 controlled-delegatecall Controlled delegatecall destination High Medium
7 reentrancy Reentrancy vulnerabilities High Medium
8 locked-ether Contracts that lock ether Medium High
9 const-func Constant functions changing the state Medium Medium
10 tx-origin Dangerous usage of tx.origin Medium Medium
11 assembly Assembly usage Informational High
12 constable-states State variables that could be declared constant Informational High
13 external-function Public function that could be declared as external Informational High
14 low-level-calls Low level calls Informational High
15 naming-convention Conformance to Solidity naming conventions Informational High
16 pragma If different pragma directives are used Informational High
17 solc-version Old versions of Solidity (< 0.4.23) Informational High
18 unused-state Unused state variables

Printers

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

Num Printer Description
1 call-graph Export the call-graph of the contracts to a dot file
2 contract-summary Print a summary of the contracts
3 function-summary Print a summary of the functions
4 human-summary Print a human-readable summary of the contracts
5 inheritance Print the inheritance relations between contracts
6 inheritance-graph Export the inheritance graph of each contract to a dot file
7 slithir Print the slithIR representation of the functions
8 vars-and-auth Print the state variables written and the authorization of the functions

Tutorial

Copyright (C) 2018 trailofbits

Tags: slither