Security incident · 2020-06-28
Balancer
According to the public DefiLlama incident dataset, Balancer (Ethereum) suffered a security incident on 2020-06-28, with about $500K reported lost.
| Date | 2020-06-28 |
|---|---|
| Reported loss | $500K |
| Chain | Ethereum |
| Target type | DeFi Protocol |
| Technique class | Token & Share Accounting |
| Technique | Incorrect Share Accounting |
| Bridge incident | No |
| Within 2020 | #29 by loss that year, 0.0% of all reported losses that year |
How this kind of attack works
The contract's bookkeeping was wrong, for example the conversion between shares and assets, so the attacker redeemed far more than they put in.
Would a pre-payment check have helped
Accounting and share-math bugs are contract-layer problems for code audits.
Other incidents with the same technique
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- Euler V12023-03-13 · $197.0M
- Compound V22021-09-29 · $147.0M
- Balancer V22025-11-03 · $128.0M
- Tectonic2026-08-30 · $124.5M
- Elrond2022-06-05 · $113.0M