Top 7 Smart Contract Issues: How to Prevent

In today’s techno-savvy world, smart contracts have become nothing less than a boon for everyone. You can find the use cases of smart contracts in almost all the sectors, such as gaming, DeFi, healthcare, insurance, NFT, financial data, recording, logistics, etc. These programs are stored on different blockchains and run when all the predetermined conditions are met. 

Security is a major concern for everyone in the dynamic crypto space surrounding smart contracts. So many issues in these contracts later become expensive exploits for hackers. Smart contract auditing is the answer if you’re wondering what can save you from this situation. 

This blog will walk you through the issues you need to eliminate from smart contracts. Also, we will discuss some ways how you can prevent them. So let’s begin. 

What Are The Issues? 

First, let us talk about smart contract issues so you know what the issues are that you need to be careful about. 

These are: 

• Arithmetic errors of integers

It is the first key vulnerability you can find in smart contracts. There is a lack of floating point support in them, which is why smart contracts represent values as integers.

Developers today are well aware of the possibility of integer overflow. 

The integers represented in the computer also have a maximum value, and whenever this number is achieved, they go back to the beginning and start from the minimum value. An extremely high number will result from subtracting 4 from 3 in an unsigned integer, which will also overflow. This possible issue, which may be prevented by utilizing a secure math library, is often known to developers. It is similar to how a car’s mileage is expressed.

• Block gas limit vulnerabilities

Because of the block gas limit, Ethereum doesn’t let the block grow too large. This only indicates a cap on the gas transactions in these blocks may use. In other words, if a transaction uses less gas, it will never run into problems or be complete.

This occurs when the number of components in the assembly rises, often during production rather than testing.

Because the test dataset is typically less than the production dataset, this vulnerability is extremely serious even if the affected contracts typically pass unit testing and function well with few users. However, they will fail as the project advances and the volume of data rises. In this situation, employing regular payments may impact the funds, making their recovery difficult.

• Frontrunning

Blockchain offers complete transparency with transactions. Frontrunning is the occupation of all those transactions that still need to be confirmed.

Interested traders may keep track of their contents and “advance” the transaction by paying more fees. This is highly frequent in decentralized financial systems and is simple to automate.

To tackle these kinds of issues, substantial reworking or redesign is sometimes necessary.

• Lack of precondition controls or parameters

Another simple but frequently occurring programming error is failing to validate function arguments or neglecting to do the appropriate tests to ensure that an action is legitimate. Typically, this pertains to address parameters that are not checked against address zero or, for example, whether an unauthenticated user has a sufficient token balance to carry out a certain transaction.

Oversight in the design process is the main cause of such errors. Therefore, it’s useful if you write all the instructions for functions, operations you need to perform, the parameters, and preconditions. Another helpful way to deal with this vulnerability is to stick to design patterns like Check-Effect-Interaction. 

• Logic Bugs

The four things mentioned above are more geared toward smart contracts, but additional things are still fundamental to programming. The most frequent issue is typically a simple mistake in the smart contract’s logic. These mistakes, which have a significant impact on security, might be the result of simple typographical errors or specification ambiguities.

Additonal Read : How to make NFTs

• Floating Pragma

The first piece of code in a solidity code that establishes the smart contract’s compiler version is most likely a solidity pragma.

Floating Pragma provides an array of compiler versions for a smart contract compilation.

A pragma can only tell the compiler to check to see whether it matches the Pragma; it can no longer alter the compiler’s version. If the result is bad, the compiler produces an error.

• Divide before multiplying

You will be able to understand this better with the help of a mathematical example.

A=(10*30*18)/30=180

Now, let us solve this again by first dividing and then multiplying. 

A=(10/30)*30*18-179.99999

Though the answers are quite close, they are still different.

Sum up:

It is a well-acknowledged fact that smart contracts are the backbone of the blockchain space, with its ever-widening number of use cases in different sectors. With the use of blockchain, it is inevitable to overlook the vulnerabilities in smart contracts. 

To escape the fear of hackers turning these vulnerabilities into expensive exploits, you only need to get reliable smart contract audit services