Casper Network Resumes Operations After Halted Due to Attack on July 26

The Casper network has resumed operations after being halted for a few days due to an attack on 26 July.

On 26 July, an attacker managed to conduct illicit transactions on the Casper network before the core team noticed suspicious activity and halted the network. The attacker was able to transfer tokens due to a vulnerability that allowed a contract installer to bypass the access rights check on urefs. This enabled the attacker to grant the contract access to uref based resources, escalating their privileges and allowing them to transfer tokens illicitly.

The core team identified the vulnerability and offered a fix, which validators had to manually update. After updating their nodes, validators scanned the entire chain for illicit transactions from its genesis block. 64 Casper validators, representing 85% of the CSPR tokens staked in the network, unanimously agreed to restart the network. As the network kicked off again, two blocks consisting of four transactions that led to the attack were orphaned. A total of 13 wallets were affected by the attack, with the Casper team making them whole in the wake of the breach.