Hack history / 2021 / Hack or exploit
flash.sx / vaults.sx
Hack or exploit on May 14, 2021 · Reentrancy
SOURCES AGREE ON DATE AND LOSS · 2 SOURCES
Lost
$13M
sources: $11.7M to $13M
Returned
none listed
as the sources state it
Rank
#255
among thefts by dollars lost
What happened
A reentrancy vulnerability in vaults.sx's flashloan contract allowed an attacker to recursively extract 1.18M EOS and 462K USDT. The attacker distributed funds across 246 accounts attempting to evade recovery. EOS BPs froze accounts by supermajority consensus and the attacker was social-engineered into nulling their keys; all users were made whole.
Details
- Date
- May 14, 2021
- Kind
- Hack or exploit
- Method
- Reentrancy
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- EOS
After the theft
- Frozen
- yes, amount not stated
“EOS BPs froze accounts by supermajority consensus and the attacker was social-engineered into nulling their keys;” (DefiLlama) - Victims reimbursed
- yes, amount not stated
“all users were made whole.” (DefiLlama)
Reported by
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Cite this page
SwanBluechip, "flash.sx / vaults.sx hack, May 14, 2021: $13M lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht7c4af3da36/ (data as of 2026-11-01).