Submitted by ronnyx2017
Attacker can make the CurveVolatileCollateral enter the status of IFFY/DISABLED. It will cause the basket to rebalance and sell off all the CurveVolatileCollateral.
The CurveVolatileCollateral overrides the _anyDepeggedInPool function to check if the distribution of capital is balanced. If the any part of underlying token exceeds the expected more than _defaultThreshold, return true, which means the volatile pool has been depeg:
And the coll status will be updated in the super class CurveStableCollateral.refresh():
The attack process is as follows:
I think the de-pegged status in the volatile pool may be unimportant. It will be temporary and have little impact on the price of outside lp tokens. After all, override the _anyDepeggedOutsidePool to check the lp price might be a good idea.
Context
tbrent (Reserve) confirmed
Reserve Mitigated:
Status: Mitigation confirmed. Full details in reports from  ronnyx2017, RaymondFam and bin2chen.
