20 Blockchain Security Vulnerabilities - An Overview

Blockchain technology is one of the most trending emerging technology in the industry. Most people assume blockchain is the solution to all problems.

Although cryptocurrency and smart contracts are the success stories of blockchain technology, researchers are still cautious about using technology in other sectors. The main reason for caution is that the technology is still not mature.

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In this article, we will summarize major 20 blockchain security vulnerabilities and attacks:

1. 51% Attack - In this type of attack, bad people have more than 50% of the network's mining hash rate. The major implication is the unauthorized addition or alteration of data to the block.
2. Double Spending Attack - This attack signifies one asset can be transacted twice. You can understand this by spending the same cryptocurrency twice without a balance update in the cryptocurrency Blockchain system. In this type of attack, an incorrect transaction happens by an authorized person.
3. Sybil Attack - Here, the attacker creates fake nodes, accounts, etc., and outcasts honest nodes by using them.
4. DNS Attack - It refers to an attacker taking advantage of known vulnerabilities available in the domain name server. This type of attack affects the availability and integrity of data.
5. SQL Injection - This type of attack helps the attacker to insert an SQL query into the web application.
6. Communication Channel Hijacking Attack - If the communication channel is not secure, an attacker can sniff data, resulting in the disclosure or alteration of data.
7. Phishing Attack - Here, an attacker uses social engineering techniques to trick the victim into clicking on a malicious link. This attack is abundant in using any technology.
8. Malware Attack - This attack compromises the victim's system and extracts credentials such as public/private key pairs, passwords, etc.
9. Distributed Denial of Service attack (DDOS) - This attack cripples the resources by sending thousands of requests in a short duration of time. Bad people want to disconnect mining pools, e-wallets, or cryptocurrency exchanges here.
10. Reentrancy Vulnerability - This type of vulnerability is a commonly found and most destructive attack in Smart Contracts.
11. 3rd Party Authentication Bypass Attack - In this type of attack, an attacker accesses victims' accounts by evading 2nd-factor authentication.
12. Transaction Malleability Vulnerability - This type of attack is caused when Blockchain does not properly validate the data transaction hash.
13. Timestamp Dependence Vulnerability - If validation is not implemented for the timestamp generated by the miners, this vulnerability may cause manipulation of resources and timestamps.
14. In-secure implementation of Cold/Hot Storage - If blockchain system resources at hosted data centers are not secure enough, this type of vulnerability allows attackers to steal data.
15. Public & Private Key Pair Theft Attack - Here, bad people may steal public and private key pairs by compromising the victim system. Methods may be system exploits, malware, phishing emails, etc.
16. Cross Function Race Condition Vulnerability - In this type of vulnerability, the attacker exploits the blockchain system's behavior that depends on the timings of uncontrollable events.
17. Self-Destruction Attack - This type of attack is commonly found in smart contracts.
18. Code Execution Attack - If the attacker successfully executes malicious code on a blockchain system, it may exploit the complete system.
19. BGP Hijacking Attack - Here, the Attacker exploits the vulnerabilities in the border gateway protocol
20. Selfish Mining Attack - This type of attack enables attackers to get undue rewards and waste honest miners' processing power.