Hack history / 2021 / Hack or exploit
Polkatrain
Hack or exploit on Apr 5, 2021 · Reward Logic Flaw
SOURCES AGREE ON DATE AND LOSS · 2 SOURCES
Lost
$3M
dollars at the time
Returned
none listed
as the sources state it
Rank
#603
among thefts by dollars lost
What happened
The POLT_LBP contract's rebate mechanism lacked maximum rebate limits or exhaustion checks. An attacker repeatedly called the swap function to extract rebate rewards, draining 57K DOT (~$3M) from the contract. The contract's _update function failed to validate rebate constraints.
Details
- Date
- Apr 5, 2021
- Kind
- Hack or exploit
- Method
- Reward Logic Flaw
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- Polkadot
Reported by
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Cite this page
SwanBluechip, "Polkatrain hack, Apr 5, 2021: $3M lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht240191b353/ (data as of 2026-11-01).