Gains Network Fork Bug Allowed Traders To Profit 900% On Every Trade: Report

• A fork of the Gains Network, a DeFi product ecosystem on Polygon and Arbitrum, had a bug that allowed traders to claim 10X gains on every trade.
• Blockchain security experts highlighted the bug in an April 19 report.
• Several teams managing Gains forks have been informed of the vulnerabilities and have taken steps to ensure their protocols are no longer vulnerable.

A bug in a fork of the Gains Network allowed traders to profit 900% on every trade, regardless of the price of their tokens traded, according to a report by blockchain security experts.

The Gains Network Infinite Money Glitch

The Gains Network, which has a total value locked (TVL) of $20.29 million and has handled $25 billion in derivatives trading volume since its inception in May 2023, was found to have a bug in a fork of its protocol. This bug allowed an attacker to place an arbitrarily high buy limit order and win every trade automatically. The bug worked by storing the stop-loss price in the protocol’s “currentPrice” variable, which calculates profit and loss. If users set their stop/loss price above the open price, they could freely profit from the trade, without risk.

How the Bug Worked

For instance, if Bitcoin’s price was $60,000, and the trader entered $59,000 as their open price, and $61,000 as their stop/loss. If the price fell to $59,000, the trade would be opened, but the price would immediately be below the trader’s stop-loss, triggering an immediate exit. Normally, this should result in exactly $0 in profit for the trader. However, since the stop-loss price of $61,000 was set as the protocol’s “current price”, the system recorded $2000 in profit for the user.

Addressing the Bug

An attacker could potentially drain the protocol of its funds by conducting enough trades with high enough stop/loss numbers. While the protocol did contain a check to stop those trying to set their stop-loss above their buy-order open price, other exploits were found allowing attackers to bypass the check. According to Zellic, traders could have scored a guaranteed profit of 900% using certain figures. This bug was only found within a fork of Gains Network, rather than Gains itself. However, a bug that impacted a previous version of the actual Gains protocol, letting traders profit 900% on sell orders, was also discovered.

Conclusion

Zellic informed multiple teams managing Gains forks including Gambit Trade, Holdstation Exchange, and Krav Trade of the vulnerabilities, and all have ensured that their protocols are no longer vulnerable. Other forks, however, could still be at risk of loss. This incident underscores the importance of rigorous security checks and measures in the world of DeFi, where bugs and vulnerabilities can have significant financial implications.