bareli - wrong implement of "is_liquidatable"

[sherlock-admin2]

bareli

Medium

wrong implement of "is_liquidatable"

Summary

if pnl.remaining ==required then it will be liquidatable.

Vulnerability Detail

def is_liquidatable(position: PositionState, pnl: PnL) -> bool:
"""
A position becomes liquidatable when its current value is less than
a configurable fraction of the initial collateral, scaled by
leverage.
"""
# Assume liquidation bots are able to check and liquidate positions
# every N seconds.
# We would like to avoid the situation where a position's value goes
# negative (due to price fluctuations and fee obligations) during
# this period.
# Roughly, the most a positions value can change is
# leverage * asset price variance + fees
# If N is small, this expression will be ~the price variance.
# E.g. if N = 60 and we expect a maximal price movement of 1%/minute
# we could set LIQUIDATION_THRESHOLD to 1 (* some constant to be on the
# safe side).
percent : uint256 = self.PARAMS.LIQUIDATION_THRESHOLD * position.leverage
required: uint256 = (position.collateral * percent) / 100
@>> return not (pnl.remaining > required)

Impact

pnl.remaining ==required then it will be liquidatable.

Code Snippet

https://github.com/sherlock-audit/2024-08-velar-artha/blob/main/gl-sherlock/contracts/params.vy#L138

Tool used

Manual Review

Recommendation

return not (pnl.remaining >= required)

Duplicate of #17