Submitted by xiaoming90, also found by unforgiven
Assume that Alices router has large amount of liquidity inside.
Assume that the Connext Admin decided to remove a router owned by Alice. The Connext Admin will call the RoutersFacet.removeRouter function, and all information related to Alices router will be erased (set to 0x0) from the s.routerPermissionInfo.
RoutersFacet.sol#L293
Alice is aware that her router has been removed by Connext Admin, so she decided to withdraw the liquidity from her previous router by calling RoutersFacet.removeRouterLiquidityFor.
However, when Alice called the RoutersFacet.removeRouterLiquidityFor function, it will revert every single time. This is because the condition msg.sender != getRouterOwner(_router) will always fail.
RoutersFacet.sol#L490
Since the RoutersFacet.removeRouter function has earlier erased all information related to Alices router within s.routerPermissionInfo, the getRouterOwner function will always return the router address.
In this case, the router address will not match against msg.sender address/Alice address, thus Alice attempts to call removeRouterLiquidityFor will always revert.
RoutersFacet.sol#L212
Router owner who provides liquidity could be rugged by Connext admin. When this happen, the router owner funds will be struck  within the RoutersFacet contract, and there is no way for the router owner to retrieve their liquidity.
In the worst case scenario, a compromised Connext admin could remove all routers, and cause all liquidity to be struck within RoutersFacet and no router owner could withdraw their liquidity from the contract. Next, the RouterFacet contract could be upgraded to include additional function to withdraw all liquidity from the contract to an arbitrary wallet address.
The router owner is still entitled to their own liquidity even though their router has been removed by Connext Admin. Thus, they should be given the right to take back their liquidity when such an event happens. The contract should update its implementation to support this. This will give more assurance to the router owner.
jakekidd (Connext) acknowledged and commented:
jakekidd (Connext) confirmed and commented:
0xleastwood (judge) commented:
