Incident Overview
Bearn DAO exploited through price manipulation attack on BSC, leading to a loss of approximately $769,000 in assets.
Bearn DAO, a decentralized reserve currency protocol on the Binance Smart Chain, was exploited on December 6, 2023. A vulnerability in the smart contract allowed the attacker to manipulate token swap ratios and execute a profitable sandwich attack. The attacker exploited the BvaultsStrategy contract's convertDustToEarned function, which relied on the current balance of the `wantToken` token.
By manipulating the ALPACA/WBNB pool and invoking the convertDustToEarned function, they artificially inflated the swap ratio, resulting in a loss of approximately $768,358 worth of assets. The exploiter then swapped the stolen BUSD to WBNB via 1inch, sent it to another EOA, and deposited it into TornadoCash. The Bearn team sent an on-chain message to the attacker, requesting a refund of a portion of the stolen funds to reimburse affected users.
Attacker Address:
https://bscscan.com/address/0xCE27b195…328dd5
Malicious Transaction:
https://bscscan.com/tx/0x51913be3…1edd5f
Malicious Contract Address:
https://bscscan.com/address/0xe1997bC9…4fDAaa
Onchain Message from BearnDAO Team:
https://bscscan.com/tx/0xc0300811…cdc942
TornadoCash Deposit Transaction:
https://bscscan.com/tx/0x25892a61…070904
Incident Report
Protocol Information
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.
What Auditors Should Check
If you're auditing a protocol with similar architecture to BearnDAO, these are the critical security checks that could have prevented this incident (December 2023).
- Verify all logic paths related to Other are guarded by proper access controls and input validation
- 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 TrialSources & References
Learn to Prevent the Next BearnDAO
The BearnDAO 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.