What is Vulnerability?
Vulnerability can be described as a unit of a system that can be exploited by an attacker to reveal the weakness in the system. When such weakness is revealed, the system can be open to different attacks.
The following are some of the vulnerabilities of blockchain technology and how they are categorized based on their layers and the solutions to mitigate them.
1. Protocol Layer Vulnerabilities (Consensus)
Race Attack: This is the kind of attack by malicious hackers by sending a transaction to the receiver and simultaneously, the attacker sends the same amount to themselves to void the payment.
Solution: The receiver will fall victim if they don’t affirm the transaction before completing the payment.
Long-Range Attack: A long-range occurs when an attacker tweaks the confidentiality of the history of a chain. The attacker can add multiple transactions as the new chain becomes longer than the valid chain.
Solution: The receiver can be protected against this attack by waiting for more block confirmation before completing the payment.
Censorship: The validators of a blockchain can act personally by not adding some ready transactions into a block. This censorship threatens the decentralized nature of blockchain technology.
Solution: The community can punish such unfair validators. Also adopting the Zero Knowledge (ZK) approach is better because it will hide the identity of whoever is behind a transaction.
51% Attack: It occurs when a single entity has too much computational power or staking. The entity can dominate and make major decisions on the chain.
Solution: The community can prevent this blockchain vulnerability by ensuring that no single person has a higher percentage of authority in the network.
- Network Layer Vulnerabilities (P2P)
Eclipse Attack: This is a highly severe vulnerability that an adverse effect can exploit and manipulate the nodes one after the other. The attacker will disconnect a node from a network and reconnect it to other malicious nodes. It leads to the compromise of incoming and outgoing data
Solution: The team can create a highly secure redundancy link to a node. Also, penetration testing can be used to double-check the security.
Timejacking: This occurs when an adversary corrupts the timestamp of a node to disconnect it from its peers. Then adopt the take timestamp to connect the node to a dubious alternative blockchain.
- Data Layer Vulnerabilities
Cryptographic Attack: This a form of attack that comes in various ways viz Man in the Middle attack, Brute Force, and others.
Solution: Checkmate by avoiding using random encryption libraries.
Length Extension Attack: This is a form of attack that occurs when an attacker can successfully calculate the length of a hash function and send it as the original data.
Solution: Avoid the use of Merkle-Damgard construction for a function.