TheBlock
An attacker minted 10 million CYS on BNB Chain by exploiting Cysic's cross-chain bridge, then sold 7.2 million tokens and moved about $727,000 in proceeds to Ethereum. Cysic blacklisted the receiving address 76 minutes after the exploit, freezing the remaining 2.8 million CYS. The project said its mainnet and existing user assets were not affected.
Why it matters
The incident targeted the bridge's message-processing and minting functions rather than Cysic's mainnet. The Cysic Foundation said the attacker gained unauthorized access to a database used by bridge-support services and submitted a fraudulent mint message.
The unauthorized tokens were sold in two rounds. The attacker received about 588,315 USDT for 5.65 million CYS and about 220 BNB for the remaining 1.55 million. Twelve of the 15 sales were routed through OKX's DEX aggregator across venues including PancakeSwap.
Market impact
The attacker moved the proceeds across SWFT, Mayan and deBridge, receiving about 306.6 ETH on Ethereum before sending almost all of it to a second wallet. Cysic's blacklist applies only to CYS on BNB Chain, so the ether remains transferable.
The bridge will stay closed pending a security review. Cysic has not published a final dollar-loss figure, noting that the number of minted tokens does not alone determine the loss. The follow-up report is expected to address verified losses and fund tracing.
Frequently asked questions
-
How did the attacker exploit Cysic's bridge?
The attacker gained unauthorized access to a database supporting the bridge and used a vulnerability in its processing logic to submit a fraudulent mint message.
-
How many CYS tokens were minted and sold?
The attacker minted 10 million CYS and sold 7.2 million before Cysic blacklisted the receiving address. The remaining 2.8 million CYS were frozen.
-
How much value moved to Ethereum?
The attacker moved about 306.6 ETH to Ethereum, worth roughly $727,000 at Sunday's ETH price of about $2,372.
-
Did the exploit affect Cysic's mainnet or user assets?
Cysic said the incident was confined to the bridge's message-processing and minting functions. The foundation said the mainnet and existing user assets were not affected.
-
What is Cysic doing after the bridge exploit?
Cysic suspended the bridge, hired a security firm to investigate and trace the funds, and said it will keep the bridge closed until a security review is complete.
CoinDesk
CryptoSlate
WuBlockchain
Crypto Rank News
Lookonchain