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Security Audit
June 17, 2024
Version 1.0.0
Presented by 0xMacro
This document includes the results of the security audit for Cannon's smart contract code as found in the section titled ‘Source Code’. The security audit was performed by the Macro security team on June 3rdth to June 4th 2024.
The purpose of this audit is to review the source code of certain Cannon 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 |
|---|---|---|---|---|
| Low | 1 | - | - | 1 |
Cannon was quick to respond to these issues.
Our understanding of the specification was based on the following sources:
Trusted Entities:
Registry Owner: Has permission to upgrade the contract, and can set the publishing and registering fees.
Package owner:
When a package is registered an owner is set that can publish, unpublish, set publishers, and nominate a new owner, on ETH mainnet.
Publishers:
Set by the owner of the package, and can have different publishers on mainnet or optimism. Have the ability to publish and unpublish on the package they have privileges for.
The following source code was reviewed during the audit:
3e60f39e7b3320f45fd62e8fc7f43ebf8cdf420d
Specifically, we audited the following contracts within this repository.
| Contract | SHA256 |
|---|---|
| contracts/CannonRegistry.sol |
|
| contracts/ERC2771Context.sol |
|
| contracts/EfficientStorage.sol |
|
| contracts/OwnedUpgradable.sol |
|
| contracts/Proxy.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. |
When registering a package, via setPackageOwnership() the package name is validated to have expected characters and a set format:
/**
* @notice Determines if the given _name can be used to register a package
* @param _name the string to check if its a valid package name for registration
*/
function validatePackageName(bytes32 _name) public pure returns (bool) {
// each character must be in the supported charset
for (uint256 i = 0; i < 32; i++) {
if (_name[i] == bytes1(0)) {
// must be long enough
if (i < MIN_PACKAGE_NAME_LENGTH) {
return false;
}
// last character cannot be `-`
if (_name[i - 1] == "-") {
return false;
}
break;
}
// must be in valid character set
if (
(_name[i] < "0" || _name[i] > "9") &&
(_name[i] < "a" || _name[i] > "z") &&
// first character cannot be `-`
(i == 0 || _name[i] != "-")
) {
return false;
}
}
return true;
}
Reference: CannonRegistry.sol#L410-L444
This will accept a package name with up to 32 characters, with a limited character set, and some exceptions. Cannon scripts take in a string value for the name, and convert it to a bytes32 value. In doing so, it only accepts strings with less than 32 characters to it can insert a null terminator character at the end. In the case where a package is registered directly, or outside cannon, inputting a package name of length 32, and without a null terminator, then cannon will currently fail to be able to use this package name in its scripts.
Remediations to Consider
Either adjust cannon to handle 32 character strings with no null terminator, or explicitly require the last character is bytes(0) in validatePackageName() to ensure all package names work as expected.
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 Cannon 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.