Cysic suspended its cross-chain bridge on Oct. 18 after an unauthorized mint of 10,000,000 CYS on BNB Smart Chain, the project said in an incident statement. The pause takes the bridge offline while the project investigates preliminary findings that point to unauthorized database access and a flaw in bridge message processing.
Cysic said its mainnet and existing user-wallet assets were unaffected. The suspension followed an incident that began the previous day, with on-chain activity indicating that most of the newly minted tokens had been moved or sold before the recipient address was blacklisted.
Unauthorized 10 million CYS mint prompts BNB Chain bridge suspension
Cysic said preliminary findings pointed to suspected unauthorized database access and a flaw in bridge message processing, while providing no further technical detail on how they were exploited or a completed account of the attack. The project suspended the cross-chain bridge connected to BNB Smart Chain pending a security review, preventing further use during that review. Cysic said its mainnet and existing user-wallet assets were unaffected; the incident involved the unauthorized creation of CYS tokens on BNB Smart Chain through the bridge.
About 7.2 million CYS moved before the receiving address was blacklisted
The unauthorized mint occurred at 12:31:38 UTC on Oct. 17, according to The Block. Cysic blacklisted the receiving address at 13:47:52 UTC, leaving about 2.8 million CYS frozen at that address.
That timing means roughly 7.2 million of the 10 million unauthorized tokens were sold or moved before the blacklist was applied, based on on-chain data reviewed by the publication. The activity also sent roughly 306.6 ETH, valued at about $727,000, to Ethereum through multiple bridges.
The figures show what was observed moving on-chain and what amount was frozen at the recipient address. They do not, however, establish where funds that had already moved ultimately went or whether they were recovered.
Security review and fund tracing
Cysic has hired an external security firm to investigate the attack path and trace the funds, according to Crypto Briefing. The bridge will remain suspended pending the security review.
No reopening date or recovery plan was announced in the information available. The investigation will focus on both the bridge’s message-processing issue and the trail of assets moved after the unauthorized mint.
