ChainLink Token (LINK) security audit, conducted by the Callisto Network Security Department in April 2019.


 

ChainLink Token (LINK) Specificities

 

 

Token Description

Symbol      : LINK
Name        : ChainLink Token
Total supply: 1,000,000,000
Decimals    : 18 
Standard    : ERC677

Deployed at:

https://etherscan.io/address/0x514910771af9ca656af840dff83e8264ecf986ca#code

Source Code:

https://gist.github.com/yuriy77k/c3a70d212a7f9ecda715252e45073158

Platform:

ETH

Number of lines:

160

 


ChainLink (LINK) Smart Contract Security Audit Report

Are Your Funds Safe?


 

1. In scope

2. Findings

In total, 2 issues were reported including:

  • 2 low severity issues.

No critical security issues were found.

2.1. Known vulnerabilities of ERC-20 token

Severity: low

Description

  • It is possible to double withdrawal attack. More details here.
  • Lack of transaction handling mechanism issue. WARNING! This is a very common issue and it already caused millions of dollars losses for lots of token users! More details here.

Recommendation

Add the following code to the transfer(_to address, ...) function:

require( _to != address(this) );

2.2. No zero address checking

Severity: low

Description

  • In functions transfer(Line 81) and transferFrom(Line 118) there are no zero address checking.

Code snippet:

https://gist.github.com/yuriy77k/c3a70d212a7f9ecda715252e45073158#file-linktoken-sol-L81

https://gist.github.com/yuriy77k/c3a70d212a7f9ecda715252e45073158#file-linktoken-sol-L118

3. Conclusion

The audited smart contract can be deployed. Only low severity issues were found during the audit.

4. Revealing audit reports

https://gist.github.com/yuriy77k/18f0b9562bfba4210550f251d91fe2ca

https://gist.github.com/yuriy77k/6ea910cccecf1c44f93b0551a474db51

https://gist.github.com/yuriy77k/6a6833c14f6a688eb142a00fd50630d9

Appendix

Smart Contract Audits by Callisto Network.

Miscellaneous

Why Audit Smart Contracts?

Our Most Popular Audit Reports.


Trust The Blockchain, Audit Your Smart Contracts.


Follow Callisto’s Security Department on Twitter to get our latest news and updates!