Beedle - Oracle free perpetual lending

Summary

Some methods make external calls within loops, which makes them vulnerable against DOS attacks. These lines are:

Vulnerability Detail

Methods repay and seizeLoan in Lender.sol make external calls inside loops. If one of the called contracts has a fallback function that reverts, it can cause the entire operation to fail.

Impact

Increased vulnerability to malicious contracts and potential deadlock.

Tools Used

Slither

Recommendation:

Use pull strategy. Instead of directly sending funds, the contract simply records the amount of collateral each user is allowed to withdraw. Then, each user is responsible for initiating a transaction to pull or withdraw their collaterals.