Hack history / 2021 / Hack or exploit
Yearn Finance
Hack or exploit on Feb 4, 2021 · Spot Price Manipulation
ATTACK TX CONFIRMED ON CHAININ REVIEWSOURCES AGREE ON DATE AND LOSS · 5 SOURCES
Lost
$11M
dollars at the time
Returned
none listed
as the sources state it
Rank
#285
among thefts by dollars lost
What happened
On February 4, 2021, attacker used flashloans to acquire 215,000 ETH, then deposited borrowed USDC/DAI into Yearn's yDAI vault at manipulated exchange rates without sufficient slippage protection. The vault lost $11M; attacker profited ~$2.7M after $3.5M in fees.
In review: possible duplicate within one source.
Details
- Date
- Feb 4, 2021
- Kind
- Hack or exploit
- Method
- Spot Price Manipulation
- How in
- Price, oracle and governance
- Target
- DeFi protocol
- Chains
- Ethereum
- Audit (rekt.news)
- unaudited
Related incidents
Yearn Finance 2025 · Hack or exploit · $300K
Yearn Ether 2025 · Hack or exploit · $9M
Yearn Finance accidentally swaps its entire Ip-yCRVv2 treasury, asks nicely for the money back 2023 · Hack or exploit · $1.5M
Yearn Finance 2023 · Hack or exploit · $11.6M
Yearn Finance 2023 · Hack or exploit · $1.4M
Yearn Ether 2025 · Hack or exploit · $9M
Yearn Finance accidentally swaps its entire Ip-yCRVv2 treasury, asks nicely for the money back 2023 · Hack or exploit · $1.5M
Yearn Finance 2023 · Hack or exploit · $11.6M
Yearn Finance 2023 · Hack or exploit · $1.4M
Cite this page
SwanBluechip, "Yearn Finance hack, Feb 4, 2021: $11M lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht6295e0690d/ (data as of 2026-10-31).