● Covered by 1 source · 1 reportMedium impact1 negative
Symbiosis DeFi Exchange Hacked for $770,000 Due to Smart Contract Vulnerabilities
Key points
- Symbiosis DeFi network hacked for $770,000.
- Hacker exploited privilege escalation and negative transaction fee vulnerabilities.
- 46 billion fake syBTC minted from 25 cents.
- Fake tokens traded to drain legitimate liquidity pools.
Symbiosis DeFi Network Compromised
On September 11, the Symbiosis DeFi network, which facilitates cross-chain crypto trading, experienced a security breach resulting in a loss of at least $770,000 (9.97 BTC). The network, operational for five years and connecting approximately 50 chains, relies entirely on smart contracts for its operations.
Exploitation of Smart Contract Flaws
The attacker exploited two vulnerabilities within Symbiosis's smart contracts. The first was an undisclosed privilege escalation exploit that granted the hacker fake network administrator privileges. The second was a basic coding error: a lack of bounds checking that allowed transaction fees to be set as a negative number.
Fake Token Generation and Liquidity Drain
Using the fake administrator privileges, the hacker set the transaction fee to a negative value. By initiating 12 transactions, the negative fee added to the moved amount instead of deducting from it. This allowed the attacker to spend only 330 satoshi (about 25 cents) to mint 46 billion syBTC, a wrapped version of Bitcoin within the Symbiosis network. For context, the theoretical maximum supply of actual Bitcoin is 21 million.
Impact and Recovery Efforts
These unbacked syBTC tokens were then traded against legitimate wrapped pairs such as BTCB, cbBTC, WBTC, and RBTC, draining their respective liquidity pools. The hacker converted approximately $336,000 into cash via Uniswap before further transactions were blocked. Security firms and exchanges flagged the remaining wrapped BTC tokens, making them difficult for the thief to use. While some centralized tokens like Coinbase's cbBTC can be nullified and re-minted after legal processes, others like RBTC cannot.
Decentralized Finance Security Implications
This incident underscores the inherent risks in decentralized finance (DeFi) platforms, particularly those relying on open-source smart contracts. The transparency of smart contracts means vulnerabilities can be discovered by anyone, and fundamental coding errors can lead to significant financial losses. The event highlights the critical need for rigorous auditing and robust security practices in DeFi development.
✨ This summary was generated by AI from the outlets' reporting listed below. It is not independently verified and may contain errors — check the original sources. How BrevFeed works →
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Reporting from
The Symbiosis DeFi network was exploited for at least $770,000 after a hacker leveraged a privilege escalation flaw and a negative transaction fee vulnerability in its smart contracts. The attacker minted 46 billion fake syBTC by setting transaction fees to a negative value, then traded these unbacked tokens to drain liquidity pools. This incident highlights critical security risks in DeFi smart contract design and auditing.