Mythril

Mythril

Symbolic execution for smart contract vulnerability discovery.

When to use Mythril

Use Mythril when you want to:

• explore vulnerable transaction sequences, not just static patterns
• analyze a Solidity file or deployed address for reachable issues
• get SWC-tagged findings with traces and state setup
• confirm whether a suspicious path is symbolically reachable

Use slither for fast repo-wide triage. Use Mythril for deeper path exploration.

Installation

# Docker (upstream-recommended simple path)
docker pull mythril/myth

# Classic pip path
pip3 install mythril

Quick Start

# Analyze Solidity source
myth analyze Contract.sol

# Analyze deployed contract by address
myth analyze -a 0xDEADBEEF...

# Limit transaction depth
myth analyze Contract.sol -t 3

Core Workflow

1. Run a bounded analysis

myth analyze Contract.sol -t 3 --execution-timeout 60

Use bounded depth and timeout early to avoid wasting cycles on state explosion.

2. Read findings as execution stories

Upstream output includes:

• issue title and severity
• SWC identifier
• function name and program counter
• vulnerable source location
• transaction sequence and caller chain

That trace is the real value: it shows how a condition can be reached.

3. Re-run with tighter scope when needed

If output is noisy or slow, reduce transaction depth or compare only the contract under active review.

Good Use Cases

• validating suspicious payable/destruct logic
• sanity-checking selfdestruct, auth, and call-chain issues
• triaging high-risk paths after a slither pass
• reviewing deployed contracts when source is limited but address is known

Practical Notes

• Mythril is slower and deeper than Slither; do not start there for every repo.
• Docker is often the least painful install path.
• Combine symbolic findings with manual contract review and test reproduction.
• Use SWC IDs as starting taxonomy, not as the whole remediation story.

Caveats

• Symbolic execution can hit path explosion or timeouts quickly.
• Not every reported issue is exploitable in production context.
• Tooling around compiler/runtime versions still matters; mismatches can distort results.

Resources

No bundled scripts/, references/, or assets/. Use upstream docs for installation edge cases, command variants, and remediation links via the SWC registry.