How much was lost in the Bunny hack?

The Bunny hack resulted in $2.4M in losses on July 16, 2021.

What attack technique was used in the Bunny exploit?

The Bunny exploit utilized Flashloan Incentive Rewards Exploit. 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.

Bunny Hack

TOTAL LOST $2.4M

Medium Jul 16, 2021 Flashloan Incentive Rewards Exploit bsc

Affected Chain bsc Incident surface

Recovered - No recovery reported

All-Time Rank #602 By amount stolen

Auditors 1 Prior security audit

Incident Overview

Defi yield farming aggregator and optimizer for Binance Smart Chan (BSC) and Ethereum (ETH)

This is classified as a Flash Loans Attacks . Compare similar hacks →

Incident Report

Protocol / Project Bunny

Date of Incident July 16, 2021

Affected Chain(s) bsc

Attack Technique Flashloan Incentive Rewards Exploit

Classification Ecosystem

Primary Source View Post-Mortem

Protocol Information

Protocol Type Yield

Smart Contract Language Solidity

Official Website pancakebunny.finance/

Protocol Twitter/X @PancakeBunnyFin

Market Context at Time of Hack

Token Categories

Solana Ecosystem Pump Fun Ecosystem

Protocol Links

GitHub Telegram

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 Deep understanding of flashloan incentive rewards exploit and Solidity and EVM internals

Capital Required Seed capital to cover gas and initial position setup

On-Chain Access Ability to interact with bsc smart contracts and deploy a custom exploit contract

Protocol Analysis Identification of the exploitable vulnerability in Bunny's contract logic - root cause: ecosystem

Execution Speed Precise transaction ordering and timing to exploit the vulnerability within a single atomic block

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 Flashloan Incentive Rewards Exploit audit checklist and test coverage

Audited by Audit Report 1 — still lost $2.4M. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to Bunny, these are the critical security checks that could have prevented this incident (July 2021).

Verify all logic paths related to Flashloan Incentive Rewards Exploit are guarded by proper access controls and input validation - see the Flash Loans 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.

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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 Flash Loans Attacks examples →

Flash Loans Attacks

Sources & References

01
Source 1 https://pancakebunny.medium.com/polybunny-post-mortem-compensati…

Threat Assessment

Severity Level

MEDIUM

Attack Vector Flashloan Incentive Rewards Exploit
Root Cause Ecosystem
Year 2021

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