Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

LockeERC20.approve() and LockeERC20.permit() emit Approval events when the allowence hasn't changed #153

Open
code423n4 opened this issue Dec 6, 2021 · 2 comments
Open

LockeERC20.approve() and LockeERC20.permit() emit Approval events when the allowence hasn't changed #153

code423n4 opened this issue Dec 6, 2021 · 2 comments
Labels
0 (Non-critical) Code style, clarity, syntax, versioning, off-chain monitoring (events etc), exclude gas optimisation bug Something isn't working disagree with severity Sponsor confirms validity, but disagrees with warden’s risk assessment (sponsor explain in comments) sponsor disputed Sponsor cannot duplicate the issue, or otherwise disagrees this is an issue

Comments

@code423n4
Copy link
Contributor

Handle

pants

Vulnerability details

The functions LockeERC20.approve() and LockeERC20.permit() emit Approval events when the allowance hasn't changed and left as it was before that transaction.

Impact

There is no reason to emit these Approval events because nothing has changed in the system. Such events are only going to confuse users.

Tool Used

Manual code review.

Recommended Mitigation Steps

Emit these events only when the new allowance is different than the old one.
@code423n4 code423n4 added 1 (Low Risk) Assets are not at risk. State handling, function incorrect as to spec, issues with comments bug Something isn't working labels Dec 6, 2021
code423n4 added a commit that referenced this issue Dec 6, 2021
@code423n4
pants issue #153
cbc084d
@brockelmore brockelmore added disagree with severity Sponsor confirms validity, but disagrees with warden’s risk assessment (sponsor explain in comments) sponsor disputed Sponsor cannot duplicate the issue, or otherwise disagrees this is an issue labels Dec 6, 2021
@brockelmore
Copy link
Collaborator

At best gas optimization, but also standard practice: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/a05312f1b72acca6904ffe32ef83ccdbad20cb4f/contracts/token/ERC20/ERC20.sol#L314

@0xean
Copy link
Collaborator

0xean commented Jan 16, 2022 

0 — Non-critical: Code style, clarity, syntax, versioning, off-chain monitoring (events etc), exclude gas-optimisations.

Marking as non-critical

@0xean 0xean added 0 (Non-critical) Code style, clarity, syntax, versioning, off-chain monitoring (events etc), exclude gas optimisation and removed 1 (Low Risk) Assets are not at risk. State handling, function incorrect as to spec, issues with comments labels Jan 16, 2022
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
0 (Non-critical) Code style, clarity, syntax, versioning, off-chain monitoring (events etc), exclude gas optimisation bug Something isn't working disagree with severity Sponsor confirms validity, but disagrees with warden’s risk assessment (sponsor explain in comments) sponsor disputed Sponsor cannot duplicate the issue, or otherwise disagrees this is an issue
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
3 participants
@0xean @brockelmore @code423n4