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Dai Security Audit Report

Dai Security Audit Report

1. Summary

Dai smart contract security audit report performed by Callisto Security Audit Department

Audit Top 200 CoinMarketCap tokens. Dai (DAI) stablecoin.

http://www.makerdao.com/

2. In scope

  1. DaiToken.sol

3. Findings

In total, ** issues** were reported including:

  • 3 low severity issues.

  • notes.

  • 4 owner privileges (the ability of an owner to manipulate contract, may be risky for investors).

No critical security issues were found.

3.1. Known vulnerabilities of ERC-20 token

Severity: low

Description

  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.

Recommendation

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

require( _to != address(this) );

3.2. Blocking transferring

Severity: owner privileges

Description

The contract owner allowed to block transfer functions( transferFrom, approve, mint, burn).

Code snippet

  • Line 234.

3.3. ERC20 Compliance — event missing

Severity: low

Description

According to ERC20 standard when coins are minted(or burned) a Transfer event should be emitted.

Code snippet

  • Lines 423, 428, 303.

3.4. Checking input addresses

Severity: low

Description

Incoming addresses should be checked for an empty value(0x0 address) to avoid loss of funds or blocking some functionality.

Code snippet

  • setOwner function (lines 129-135)
  • transferFrom function (lines 390-405)

4. Conclusion

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

5. Revealing audit reports

https://gist.github.com/yuriy77k/bf2ea7c611b07073262d216d05de3b30

https://gist.github.com/yuriy77k/8cc19398ee91c3dd236f30a5b91c2d97

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