Need an audit or want to learn more about Macro’s services?
Reach out for an audit or to learn more about Macro
Security Audit
May 21st, 2025
Version 1.0.0
Presented by 0xMacro
This document includes the results of the security audit for Superstate's smart contract code as found in the section titled ‘Source Code’. The security audit was performed by the Macro security team from May 17th to May 19th, 2025.
The purpose of this audit is to review the source code of certain Superstate Solidity contracts, and provide feedback on the design, architecture, and quality of the source code with an emphasis on validating the correctness and security of the software in its entirety.
Disclaimer: While Macro’s review is comprehensive and has surfaced some changes that should be made to the source code, this audit should not solely be relied upon for security, as no single audit is guaranteed to catch all possible bugs.
The following is an aggregation of issues found by the Macro Audit team:
| Severity | Count | Acknowledged | Won't Do | Addressed |
|---|---|---|---|---|
| High | 1 | - | - | 1 |
| Code Quality | 1 | - | - | 1 |
| Gas Optimization | 1 | - | - | 1 |
Superstate was quick to respond to these issues.
Our understanding of the specification was based on the following sources:
The following source code was reviewed during the audit:
fe65f82421133f59f2c650626eea281e59fe2073
3d7f3d7d64d323ee14327347c87bc261ee081841
Specifically, we audited the following contracts.
| Source Code | SHA256 |
|---|---|
| src/AccountingPausable.sol |
|
| src/Allowlistable.sol |
|
| src/Bridgeable.sol |
|
| src/EquityToken.sol |
|
| src/Permittable.sol |
|
| src/SuperstateTokenCore.sol |
|
Note: This document contains an audit solely of the Solidity contracts listed above. Specifically, the audit pertains only to the contracts themselves, and does not pertain to any other programs or scripts, including deployment scripts.
Click on an issue to jump to it, or scroll down to see them all.
We quantify issues in three parts:
This third part – the severity level – is a summary of how much consideration the client should give to fixing the issue. We assign severity according to the table of guidelines below:
| Severity | Description |
|---|---|
|
(C-x) Critical |
We recommend the client must fix the issue, no matter what, because not fixing would mean significant funds/assets WILL be lost. |
|
(H-x) High |
We recommend the client must address the issue, no matter what, because not fixing would be very bad, or some funds/assets will be lost, or the code’s behavior is against the provided spec. |
|
(M-x) Medium |
We recommend the client to seriously consider fixing the issue, as the implications of not fixing the issue are severe enough to impact the project significantly, albiet not in an existential manner. |
|
(L-x) Low |
The risk is small, unlikely, or may not relevant to the project in a meaningful way. Whether or not the project wants to develop a fix is up to the goals and needs of the project. |
|
(Q-x) Code Quality |
The issue identified does not pose any obvious risk, but fixing could improve overall code quality, on-chain composability, developer ergonomics, or even certain aspects of protocol design. |
|
(I-x) Informational |
Warnings and things to keep in mind when operating the protocol. No immediate action required. |
|
(G-x) Gas Optimizations |
The presented optimization suggestion would save an amount of gas significant enough, in our opinion, to be worth the development cost of implementing it. |
In the EquityToken contract, transferFrom(), when called with the destination set to the EquityToken's contract address itself, burns tokens and emits a Bridge event, which is utilized for off-chain accounting. Therefore, it's essential for reported event parameters to be correct, as sensitive downstream systems depend on these values.
However, in transferFrom(), the emitted Bridge event has the incorrect value for src parameter as it is set to msg.sender instead of src.
// Emit the bridge event manually to ensure correct parameters
emit Bridge(
msg.sender, // caller
msg.sender, // src (per the Bridge event definition)
amount,
address(0),
string(new bytes(0)),
0
);
Due to this issue, off-chain accounting may assign assets to the incorrect owner.
Remediations to consider
src parameter of the Bridge event to the correct value.In the EquityToken contract, some errors are generated by emitting custom errors (e.g., RenounceOwnershipDisabled), while in several other functions, require expression strings are used for the same (e.g., Unauthorized in _requireAuth(), _requireAllowed(), and Accounting Paused in _requireNotAccountPaused()). This differs from implementing these functions in SuperstateTokenV5, which used custom errors exclusively.
Consider replacing string errors in require expressions with Errors.
In the Bridgeable contract, the setChainIdSupport() function calls isChainIdSupported() twice: once to determine if the chain with the provided chainId is supported and once to set the oldSupported event parameter value.
This can be optimized by memorizing the result of the call to isChainIdSupported() or by setting oldSupported to the inverted boolean value - !supported.
Macro makes no warranties, either express, implied, statutory, or otherwise, with respect to the services or deliverables provided in this report, and Macro specifically disclaims all implied warranties of merchantability, fitness for a particular purpose, noninfringement and those arising from a course of dealing, usage or trade with respect thereto, and all such warranties are hereby excluded to the fullest extent permitted by law.
Macro will not be liable for any lost profits, business, contracts, revenue, goodwill, production, anticipated savings, loss of data, or costs of procurement of substitute goods or services or for any claim or demand by any other party. In no event will Macro be liable for consequential, incidental, special, indirect, or exemplary damages arising out of this agreement or any work statement, however caused and (to the fullest extent permitted by law) under any theory of liability (including negligence), even if Macro has been advised of the possibility of such damages.
The scope of this report and review is limited to a review of only the code presented by the Superstate team and only the source code Macro notes as being within the scope of Macro’s review within this report. This report does not include an audit of the deployment scripts used to deploy the Solidity contracts in the repository corresponding to this audit. Specifically, for the avoidance of doubt, this report does not constitute investment advice, is not intended to be relied upon as investment advice, is not an endorsement of this project or team, and it is not a guarantee as to the absolute security of the project. In this report you may through hypertext or other computer links, gain access to websites operated by persons other than Macro. Such hyperlinks are provided for your reference and convenience only, and are the exclusive responsibility of such websites’ owners. You agree that Macro is not responsible for the content or operation of such websites, and that Macro shall have no liability to your or any other person or entity for the use of third party websites. Macro assumes no responsibility for the use of third party software and shall have no liability whatsoever to any person or entity for the accuracy or completeness of any outcome generated by such software.