Hackers to Steal Over $20M From Misconfigured ETH Clients

Attackers used the an RPC [Remote Procedure Call] interface on port 8545
12 June 2018   1824

A group of hackers stole more than $ 20M worth ETH from wallets and minning apps based on the same-named blockade. This is reported by CoinDaily.

The attackers used Ethereum software applications that were configured to provide access to the RPC (remote procedure call) interface on port 8545.

This interface is used to access a software API that approved third-party services or applications may request the receipt of data from the source service, for example, applications for storing funds received from mining.

The RPC interface is able to provide access to some important functions, allowing a third-party application to view private keys and personal user data, and conduct transactions.

By default, it is disabled in most applications, and developers warn of the potential danger of launching it if it is not properly protected by the ACL (access control list), firewall, or other authentication systems.

Nowadays, almost all Ethereum-based software comes with an RPC interface, and in most cases, even when turned on, they are appropriately configured to listen to requests only via the local interface (127.0.0.1), meaning from apps running on the same machine as the original mining/wallet app that exposes the RPC interface.

Despite the warning of official developers, users continued to use misconfigured Ethereum clients for years. Many of them reported a loss of funds through an open RPC interface.

The scanning of these interfaces lasted for many years, but intensified with the rise in prices for cryptocurrencies. One of the biggest surges of scanning activity was registered in November last year.

The attacks were successful, as the victims soon discovered that the version of the Electrum Wallet application comes with RPC JSON, enabled by default, which makes it easy to access user tools.

According to security experts, at least one case of a massive scan of port 8545 was recorded in search of the software left on the Ethereum network.

Since March of this year, when these scans began, the attacker was able to get about 3,96234 Ethereum (about $ 2-3 thousand).

After analyzing the data of our own observations, the Netlab team concluded that the scan of port 8545 never ceased, intensified when several groups joined it. One of them turned out to be more effective than the others, assigning more than $ 20 million from Ethereum to open applications.

Satori, one of the world's largest IoT botnets, in May 2018, also began scanning for Ethereum's open air miners.

Potentional Vulnerabilities Found in ETH 2.0

Least Authority have found potentional security issues in the network P2P interaction and block proposal system
26 March 2020   983

Technology security firm Least Authority, at the request of the Ethereum Foundation, conducted an audit of the Ethereum 2.0 specifications and identified several potential vulnerabilities at once.

Least Authority said that developers need to solve problems with vulnerabilities in the network layer of peer-to-peer (P2P) interaction, as well as in the block proposal system. At the same time, the auditor noted that the specifications are "very well thought out and competent."

However, at the moment there is no large ecosystem based on PoS and using sharding in the world, so it is impossible to accurately assess the prospects for system stability.
Also, information security experts emphasized that the specifications did not pay enough attention to the description of the P2P network level and the system of records about Ethereum nodes. Vulnerability risks are also observed in the block proposal system and the messaging system between nodes.

Experts said that in the blockchains running on PoS, the choice of a new block is simple and no one can predict who will get the new block. In PoS systems, it is the block proposal system that decides whose block will fall into the blockchain, and this leads to the risk of data leakage. To solve the problem, auditors suggested using the mechanism of "Single Secret Leader Election" (SSLE).

As for the peer-to-peer exchange system, there is a danger of spam. There is no centralized node in the system that would evaluate the actions of other nodes, so a “malicious" node can spam the entire network with various messages without any special punishment. The solution to this problem may be to use special protocols for exchanging messages between nodes.