Incident Overview
On October 22, 2024, Vista Finance, a protocol on Binance Smart Chain (BSC), suffered an exploit resulting in a loss of approximately $29,000.
The exploit originated from Vista Finance’s use of the flashLoan function, which mints tokens at the beginning of the process and burns them at the end. A critical vulnerability was found in the contract's _burn function, which directly adjusted the balance within _balances[account] rather than utilizing the getFreeBalance method. This discrepancy allowed the attacker to manipulate token balances, bypassing restrictions tied to staked tokens.
By initiating a flash loan for 1,000,000 tokens, the attacker was able to buy ICO tokens from Vista Finance using $1,500 in BUSD. These ICO tokens were then sold to another address for a profit. The exploit relied on the fact that getFreeBalance did not properly account for staked status, allowing the attacker to use the flash-minted tokens to bypass the staking limitations and cash out the gains undetected.
Incident Report
Protocol Information
What the Attacker Needed to Succeed
Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.
What Auditors Should Check
If you're auditing a protocol with similar architecture to Vista Finance, these are the critical security checks that could have prevented this incident (October 2024).
- Verify all logic paths related to Flash Loan Attack are guarded by proper access controls and input validation - see the Flash Loans Attacks attack class for patterns
- Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs
Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.
Free TrialSecurity Audit History
- Audit Report 1 Report
Related Attack Classes
The technique used in this hack maps to these vulnerability classes in our security curriculum:
Sources & References
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