Jarvis + Token (JAR) security audit, conducted by the Callisto Network Security Department in October 2018.


Jarvis + (JAR) Specificities




Audit Request

The ERC20 token in before of the Jarvis+ mainnet, providing exchanges and project participants.

Symbol       : JAR
Name         : Jarvis+ Token
Total supply : 600,000,000
Decimals : 18
Standard : ERC20

Source Code:


Disclosure policy:







Jarvis+ Token (JAR) Smart Contract Security Audit Report

Are Your Funds Safe?


1. In scope

JarvisPlusToken_flat.sol github commit hash b1e9458f8a77fe13d09940547da7824f3066cf17.

2. Findings

In total, 2 issues were reported including:

  • 1 low severity issues.

  • 1 minor observation.

No critical security issues were found.

2.1. Known vulnerabilities of ERC-20 token

Severity: low.


  1. It is possible to double withdrawal attack. More details here.

  2. 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.

Code snippet:

2.2. Extra checking

Severity: minor observation.


Extra checking in 96, 165, 166 lines of BasicToken and StandardToken contracts. SafeMath library checks it anyway.

Code snippet:

3. Conclusion

The token contract is safe to be deployed, developers should consider checking ERC20 known issues.

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