Optimism quietly patches critical testnet flaws after rival’s tip-off

The Layer 2 network Optimism ON

-3.60%
fixed two critical vulnerabilities on his testnet, at least several weeks after learning about them.

Offchain Labs, which first identified the vulnerabilities, declared on Friday that Optimism updated its testnet on April 25. The since-fixed security flaws allowed bad actors to manipulate the chain’s history and conduct other “subtle attacks,” the software company said.

On March 22, Offchain Labs warned Optimism about two issues with its testnet: bad actors could force OP Stack’s tamper-resistant mechanism to accept a fraudulent chain history, and an exploiter could prevent it from accepting a correct chain history.

“These are difficult problems to solve,” Offchain Labs, a competitor of Optimism, said in the statement. It added that tamper-resistant protocols and their timing aspects are “very difficult” to design.

According to Offchain Labs, Optimism has since modified its timer handling code to fix the vulnerabilities. Certainly, Layer 2 testnets, or test networks, exist to identify networks’ security flaws before they are officially launched.