Level 5 - Token ⏺⏺
Last updated
Last updated
The exploit is due to unsafe math in older versions of Solidity. The balance can underflow and cause a huge amount of tokens to be transferred.
Sending just 1 more token than the user balance causes the value to underflow.
Submit instance... 🥳
Integer overflow/underflow in Solidity v0.6.0
This could easily be fixed using a different check instead of comparing to zero.