Root-cause analysis not yet published. The incident description below contains all currently available signal — review the attack transaction directly for definitive forensics.
Reproducible Foundry test fork from SunWeb3Sec/DeFiHackLabs. Clone the repo, run forge test against the file path above, and replay the exploit against a mainnet fork at the historical block. Use for reproduction only — not for live targets.
bZx officially tweeted that at 3:28 am Eastern time (15:30, September 13th, Beijing time), we began to study the decline in TVL of the agreement. By 6:18 AM EST (18:30, September 13th, Beijing time), we confirmed that several iTokens had repeated incidents. Lending is temporarily suspended. The duplicate method has been patched from the iToken contract code, and the agreement has resumed normal operation. According to the information of the founder of Compound, there are a total of US$2.6 million in LINK, US$1.6 million in ETH, and US$3.8 million in stablecoins, with a total of US$8 million in assets affected. 1inch co-founder Anton Bukov tweeted that the attacker had stolen about 4,700 ETH in this incident and attached the address of the stolen funds. In response, bZx said that the funds are currently not at risk. The funds listed have been deducted from our insurance fund. On September 16, bZx released an iToken repeat incident report, and the attacker has returned all funds. Attack method (per SlowMist): Replay Attack. Reported loss: -.
- chain
- —
- protocol
- bZx
- bug_class
- unknown
- date_occurred
- 2020-09-14
- loss_usd
- —
- source_id
- sm:bzx::2020-09-14