Summary

Function and action liquidate can be front run by the unhealthy account

Vulnerability Details

Liquidators are incentivized to act on user accounts that are not healthy in order to receive a bonus.
However, once a liquidator has sent a liquidation transaction, the account to be liquidated/unhealthy account can observe this and quickly deposit at a high enough fee that prioritizes their transaction, sending in just the minimal amount to restore their account health

Impact

While the above may be considered desired that unhealthy accounts who are about to be liquidated correct their accounts, this disadvantages the potential liquidator who just loses on gas fees and reducing their appetite to participate in the protocol for liquidations

Tools Used

Manual Analysis

Recommendations

It is recommended users are well informed of these risks and directed to options like Flashbots.