DODO AMM Hack

TOTAL LOST $3.8M
Medium Access Control Exploit / Other ethereum

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain ethereum Incident surface
Recovered $3.1M 81.6% returned
All-Time Rank #491 By amount stolen
Auditors 3 Prior security audits

Incident Overview

The exploits targeted several DODO V2 Crowdpools, namely the WSZO, WCRES, ETHA, and FUSI pool.

The DODO V2 Crowdpooling smart contract has a bug that allows the init() function to be called multiple times. This means that an exploiter can perform an attack with the following steps:

1. Exploiter creates a counterfeit token and initializes the smart contract with it by calling the init() function.

2. Exploiter calls the sync() function and sets the “reserve” variable, which represents the token balance, to 0.

3. Exploiter calls init() again to re-initialize - this time with a “real” token (i.e. tokens in DODO’s pools)

Exploiter uses a flash loan to transfer all real tokens from the pools and bypass the flash loan check.

The exploiter 1:

- interacted with a centralized exchange

- withdrew 0.46597 ETH from Binance: https://etherscan.io/tx/0x970b32a8…48360f

- executed, in quick succession, 7 BUSD withdrawal transactions (see the link for one example), possibly involving the Binance Bridge: https://etherscan.io/tx/0x300de107…276e93

- transferred 67,416 BUSD to 0xa305fab8…1dd645 twice: https://etherscan.io/tx/0x306d08f3…11cab5 https://etherscan.io/tx/0x56dbf642…8669cf

- transferred 59,245.324743 USDT to 0xa305fab8…1dd645 twice: https://etherscan.io/tx/0xbee2f507…2a5c13 https://cn.etherscan.com/tx/0xaf80cf58…4199b9

- executed two exploits against DODO smart contracts. The first one was against the DODO-USDT test contract, and funds were transferred to 0xa305fab8…1dd645: https://etherscan.io/address/0x328410f2…5e5c1c#tokentxns

- second one was against the WCRES-USDT contract, and funds were transferred to 0x56178a0d…345bf9: https://cn.etherscan.com/address/0x910fd17b…80be8a#tokentxns

The exploiter 2:

- executed 3 exploits against DODO contracts:

1. ETHA-USDT: https://etherscan.io/tx/0x0b062361…d92428

2. WSZO-USDT: https://etherscan.io/tx/0xff9b3b2cb09d149762fcffc56ef71362bec1ef6a7d68727155c2d68f395ac1e

3. vETH-WETH, with 93,148 gwei: https://etherscan.io/tx/0x561f7ccb…0c5c4a

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

Incident Report

Protocol / Project DODO AMM
Date of Incident
Affected Chain(s) ethereum
Attack Technique Access Control Exploit / Other
Classification Protocol Logic / Exchange (DEX)
Primary Source View Post-Mortem

Protocol Information

Protocol Type Dexs
Affected Token DODO
Smart Contract Language Solidity
Official Website dodoex.io/
Protocol Twitter/X @BreederDodo
Team Anonymous
Source Code Unverified

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 DODO AMM'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 Access Control Exploit / Other audit checklist and test coverage
Audited by Trail of Bits, Certik, DeFi Safety — still lost $3.8M. Prior audits don't guarantee safety, especially after post-audit code changes.

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

  • Verify all logic paths related to Access Control Exploit / Other 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.

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Funds Recovery

81.6%

Recovered

$3.1M

Net Loss

699200

Security Audit History

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

Proof-of-Concept Exploits

1 PoC available
poc-exploits - dodo amm
$ DODO Flashloan Attack

On-Chain Evidence & References

Sources & References

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