Submitted by hickuphh3
PooledCreditLine.sol#L1215-L1221
Interest is calculated as
It is possible for the calculated interest to be zero for principal tokens with small decimals, such as EURS (2 decimals). Accumulated interest can therefore be zero by borrowing / repaying tiny amounts frequently.
Assuming a borrow interest rate of 5% (5e17) and principal borrow amount of 10_000 EURS (10_000 * 1e2 = 1_000_000), the interest rate calculated would be 0 if principal updates are made every minute (around 63s).
While plausible, this method of interest evasion isnt as economical for tokens of larger decimals like USDC and USDT (6 decimals).
Take caution when allowing an asset to be borrowed. Alternatively, scale the principal amount to precision (1e18) amounts.
ritik99 (Sublime) disagreed with High severity and commented:
HardlyDifficult (judge) decreased severity to Medium
KushGoyal (Sublime) commented:
For this contest, 18 reports were submitted by wardens detailing low risk and non-critical issues. The report highlighted below by hickuphh3 received the top score from the judge.
The following wardens also submitted reports: IllIllI, kyliek, WatchPug, 0x1f8b, robee, sseefried, BouSalman, Meta0xNull, rayn, 0xkatana, Dravee, hake, 0v3rf10w, 0xDjango, dirk_y, defsec, and gzeon.
