Wrongly implemented check in `_check` will revert even if price feed is not stale
Summary
After makin sure the sequencer is up in _validatePrice the protocol then check price difference in _check:
From the provided token feed it extract chainLinkPrice and updatedAt values via latestRountData. Then it check if price is stale.
The updateAt value represent the timestamp when the round last was updated (answer was last computed).
Vulnerability Details
The issue is that this check will revert when the price is not actually stale (when it is on the boundary of maxTimeWindow)
Consider following example:
maxTimeWindow = 60
updatedAt = 1000
block.timestamp = 1060
The condition fails and will return with stale price feed error even tho it is not stale.
If maxTimeWindow is 60 seconds, you’d expect updates within the last full 60 seconds to be valid, not just 59 seconds.
Impact
Check will return with stale price feed error even when price feed is not stale.
Tools Used
Manual Review
Recommendations
Make the following change to the _check function:
Lead Judging Commences
Admin is trusted / Malicious keepers
Please read the CodeHawks documentation to know which submissions are valid. If you disagree, provide a coded PoC and explain the real likelihood and the detailed impact on the mainnet without any supposition (if, it could, etc) to prove your point. Keepers are added by the admin, there is no "malicious keeper" and if there is a problem in those keepers, that's out of scope. ReadMe and known issues states: " * System relies heavily on keeper for executing trades * Single keeper point of failure if not properly distributed * Malicious keeper could potentially front-run or delay transactions * Assume that Keeper will always have enough gas to execute transactions. There is a pay execution fee function, but the assumption should be that there's more than enough gas to cover transaction failures, retries, etc * There are two spot swap functionalies: (1) using GMX swap and (2) using Paraswap. We can assume that any swap failure will be retried until success. " " * Heavy dependency on GMX protocol functioning correctly * Owner can update GMX-related addresses * Changes in GMX protocol could impact system operations * We can assume that the GMX keeper won't misbehave, delay, or go offline. " "Issues related to GMX Keepers being DOS'd or losing functionality would be considered invalid."
Appeal created
Admin is trusted / Malicious keepers
Please read the CodeHawks documentation to know which submissions are valid. If you disagree, provide a coded PoC and explain the real likelihood and the detailed impact on the mainnet without any supposition (if, it could, etc) to prove your point. Keepers are added by the admin, there is no "malicious keeper" and if there is a problem in those keepers, that's out of scope. ReadMe and known issues states: " * System relies heavily on keeper for executing trades * Single keeper point of failure if not properly distributed * Malicious keeper could potentially front-run or delay transactions * Assume that Keeper will always have enough gas to execute transactions. There is a pay execution fee function, but the assumption should be that there's more than enough gas to cover transaction failures, retries, etc * There are two spot swap functionalies: (1) using GMX swap and (2) using Paraswap. We can assume that any swap failure will be retried until success. " " * Heavy dependency on GMX protocol functioning correctly * Owner can update GMX-related addresses * Changes in GMX protocol could impact system operations * We can assume that the GMX keeper won't misbehave, delay, or go offline. " "Issues related to GMX Keepers being DOS'd or losing functionality would be considered invalid."
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