Hack history / 2021 / Hack or exploit
Lever
Hack or exploit on Nov 27, 2021 · Borrow Logic Flaw
SOURCES AGREE ON DATE AND LOSS · 2 SOURCES
Lost
$652K
dollars at the time
Returned
none listed
as the sources state it
Rank
#1,065
among thefts by dollars lost
What happened
Attacker exploited Lever's liability calculation to execute a flash loan attack using two malicious contracts. Contract A borrowed 2,100 BNB and deposited 2,000 into Lever's vault for interest-bearing tokens, then borrowed 1,500 BNB. Contract B received the collateral without Lever verifying that the xWBNB wasn't already used as collateral, allowing repayment with uncollateralized borrowed funds.
Details
- Date
- Nov 27, 2021
- Kind
- Hack or exploit
- Method
- Borrow Logic Flaw
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- BNB Chain
Reported by
Related incidents
Cite this page
SwanBluechip, "Lever hack, Nov 27, 2021: $652K lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht4ed00a3dbe/ (data as of 2026-10-31).