Sparkn

Summary 📌

In the ProxyFactory.sol contract, utilizing block.timestamp — specifically when creating contests with brief durations (duration <= block_creation_time_in_blockchain) — might result in a valid transactions being reverted.

Vulnerability Details 🔍

Occasionally, due to either malicious intent or not, validators might adjust the block.timestamp to a value slightly preceding the closeTime.

This leads to the the condition in setContest() (line 110) being true and executing an unintended revert:

This malfunction occurs if:

• The provided timestamp was valid: closeTime > previousBlockTimestamp

• The intended duration for the contest was an expected small one.

Impact 📈

The repercussions are little, some lost time and a small amount of gas wasted due to the unexpected reverts.

Tools Used 🛠️

• Manual audit.

Recommendations 🎯

Two potential fixes are suggested:

🚧 Note ⚠️: Given that this project is said to be deployed across diverse EVM-compatible blockchains, consider their different block creation intervals across these platforms when fixing this issue.

• 1️⃣ Abandon the concept of immediate contest conclusions and set a minimum duration equivalent to the average block creation interval on the targeted blockchain.

• 2️⃣ Evaluate, when closeTime is inferior to block.timestamp, if the time gap between block.timestamp and closeTime falls within X seconds (where X denotes the block creation interval). This ensures the reliability of genuine situations and prevents a contest from starting too early. At its extreme, a contest could kick off X seconds prior to real time, which shouldn't disrupt other features.

  Code example 💻

  🚧 Note ⚠️: This provided code has not undergone testing and is meant to serve as a guideline.

  function setContest(/*args*/) public onlyOwner

  {

  // More code...

  ​

  if (closeTime > block.timestamp + MAX_CONTEST_PERIOD) {

  revert ProxyFactory__CloseTimeNotInRange();

  }

  ​

  // 🟢 Here is the new condition 🟢

  if (closeTime < block.timestamp && block.timestamp - closeTime > AVERAGE_BLOCK_CREATION_TIME) {

  revert ProxyFactory__CloseTimeNotInRange();

  }

  ​

  // More code...

  }

For its simplicity, I particularly recommend the solution 1️⃣.