B353N - Exploitable Loan Modification in Cooler.sol

[sherlock-admin]

B353N

false

Exploitable Loan Modification in Cooler.sol

Summary

This comprehensive security review identifies a critical vulnerability within the Cooler.sol smart contract. The flaw permits a malicious lender to manipulate loan conditions by utilizing the provideNewTermsForRoll function. Subsequently, due to the absence of proper access control in the rollLoan function, the attacker can execute a loan rollover with substantially elevated interest rates.

The vulnerability unfolds in two distinct stages. Initially, the malicious lender invokes the provideNewTermsForRoll function, which allows them to tamper with the loan's interest rate and its duration. Notably, these alterations can involve setting excessively high interest rates or significantly reducing the loan duration. Following this, the absence of robust access control in the rollLoan function permits the malicious lender to execute a loan rollover with the manipulated terms, effectively imposing unfavorable conditions on the borrower.

Impact

The potential consequences of this vulnerability are substantial. Borrowers face the risk of financial loss due to the imposition of disadvantageous terms on their loans. As malicious lenders exploit the vulnerability to modify interest rates and loan durations, borrowers could experience severe financial setbacks.

Code Snippet

https://github.com/sherlock-audit/2023-08-cooler/blob/main/Cooler/src/Cooler.sol#L192-L217

Tool used

Manual Review

Recommendation

To mitingate this issue add access control on rollLoan function to can be called only by owner()

iif (msg.sender != owner()) revert OnlyApproved();

Duplicate of #26