How much was lost in the SushiSwap hack?

The SushiSwap hack resulted in $15K in losses on November 30, 2020.

What attack technique was used in the SushiSwap exploit?

The SushiSwap exploit utilized Improper Access Control. Understanding this attack vector is critical for smart contract auditors and developers building secure DeFi protocols.

How can developers prevent similar smart contract attacks?

Preventing smart contract hacks requires a combination of secure coding practices, thorough security audits, and understanding common attack vectors like reentrancy, oracle manipulation, and access control flaws. Smart Contract Hacking (SCH) provides hands-on training to help developers and auditors identify and prevent vulnerabilities before deployment.

SushiSwap Hack

TOTAL LOST $15K

Low Nov 30, 2020 Improper Access Control ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #2346 By amount stolen

Auditors 1 Prior security audit

Incident Overview

SushiSwap is the most multi-chain DEX, powered by its industry's most advanced swap and aggregation stack across 40+ chains.

This is classified as a Access Control Attacks . Compare similar hacks →

Incident Report

Protocol / Project SushiSwap

Date of Incident November 30, 2020

Affected Chain(s) ethereum

Attack Technique Improper Access Control

Classification Access Control

Protocol Information

Protocol Type Dexs

Smart Contract Language Solidity

Official Website sushi.com/

Protocol Twitter/X @SushiSwap

What the Attacker Needed to Succeed

Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.

Technical Knowledge Operational-security tradecraft (phishing, malware, leaked seed phrases, or insider access) to obtain treasury signing authority

Capital Required Minimal capital - only enough to cover gas while draining the compromised accounts

On-Chain Access Valid signing authority over the compromised wallets / multisig signers, allowing direct transfer of funds or stake authorization

Target Reconnaissance Identification of SushiSwap's high-value treasury accounts and the authority / multisig structure controlling them

Execution Speed Speed to drain the compromised accounts before the team detects the breach and revokes signing authority or freezes the assets

Obfuscation Plan A strategy to launder and move stolen funds - typically through mixers, cross-chain bridges, or decentralized DEX swaps to resist tracing

What Auditors Should Check

Could this have been caught in audit? Likely, with a thorough Improper Access Control audit checklist and test coverage

Audited by Audit Report 1, still lost $15K. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to SushiSwap, these are the critical security checks that could have prevented this incident (November 2020).

Verify all logic paths related to Improper Access Control are guarded by proper access controls and input validation - see the Access Control Attacks attack class for patterns
Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs

Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.

Free Trial

Security Audit History

Audit Report 1 Report

Related Attack Classes

The technique used in this hack maps to these vulnerability classes in our security curriculum:

See all Access Control Attacks examples →

Access Control Attacks

Threat Assessment

Severity Level

LOW

Attack Vector Improper Access Control
Root Cause Access Control
Year 2020

Learn to Prevent the Next SushiSwap

The SushiSwap hack is one of many attacks that skilled auditors are trained to detect before deployment. Master real exploit patterns and defense techniques with hands-on Web3 security training.

Start Free Trial Browse Attack Library