ArsenLupin - _stethToWsteth method revert, resulting in DoS

[sherlock-admin4]

ArsenLupin

High

_stethToWsteth method revert, resulting in DoS

Summary

stEth::safeTransferFrom could transfer 1-2 less way, which could lead to the function revert because the same amount is passed into the _stethToWsteth method.

Vulnerability Detail

DepositWrapper.sol

if (token == steth) {
IERC20(steth).safeTransferFrom(sender, wrapper, amount);
amount = _stethToWsteth(amount);

• Almost the same issue was found on the Sherlock contest.

  [Solodit](https://solodit.xyz/issues/h-2-many-cases-stethtransferfrom-will-transfer-1-2-less-way-which-would-result-in-revert-in-consequent-functions-because-of-not-enough-balance-sherlock-sophon-farming-contracts-git)

• The vulnerability discussion could be found here Account's stETH balance getting lower on 1 or 2 wei due to rounding down integer math lidofinance/lido-dao#442

Impact

Functionality DoS.

Code Snippet

https://github.com/sherlock-audit/2024-06-mellow/blob/main/mellow-lrt/src/utils/DepositWrapper.sol#L55-L57

Tool used

Manual Review

Recommendation

Use lido recommendation to utilize transferShares function. You could also check the balances (before/after) and take the delta on it.

[Senya123]

Escalate
It is a valid issue. It is a valid dup of the #299 issue, as well of others dups.
Additionaly, the same issue was found on previous contest, graded as a high issue
sherlock-audit/2024-05-sophon-judging#63

[sherlock-admin3]

Escalate
It is a valid issue. It is a valid dup of the #299 issue, as well of others dups.
Additionaly, the same issue was found on previous contest, graded as a high issue
sherlock-audit/2024-05-sophon-judging#63

You've created a valid escalation!

To remove the escalation from consideration: Delete your comment.

You may delete or edit your escalation comment anytime before the 48-hour escalation window closes. After that, the escalation becomes final.

[z3s]

Can anyone find a tx on etherscan where this happen!? because I checked dozen stETH transfers and non of them have this issue.

[blckhv]

https://docs.lido.fi/guides/lido-tokens-integration-guide/#1-2-wei-corner-case
lidofinance/lido-dao#442

[z3s]

Yeah, etherscan's Transaction Details isn't showing correct info for this issue, I should check event logs.
so depositing stETH get DoSed most of time. I think this submission and it's duplicates should be valid Mediums.

[WangSecurity]

Firstly, advice for all in this issue, if your issue is invalid and its grouped into the family, like this one with #299 being the main report, please escalate the main report.

Secondly, about the escalation. I believe this issue is not sufficient to be a valid duplicate, since it doesn't identify the root cause (why there would be 1-2 wei less?), doesn't identify a medium severity impact (functionality DOS by itself is not medium), and doesn't have a valid vulnerability or attack path.

I'll review #299 if it's indeed a valid issue, but this escalation will be rejected and deduped if #299 is valid.

[WangSecurity]

For everyone interested in #299 being valid, please look at discussion under #276 issue.

[Senya123]

@WangSecurity could you please explain why my issue is not sufficient duplicate, if it explains the same bug?

After looking deeper into #181, I see it's not a sufficient duplicate, hence, the escalation there will be rejected either way. Hence, I'll make this escalation as the main one for #299 issue family.
Plan to accept the escalation and leave the issue as it is.

[WangSecurity]

Based on my comment here:

Secondly, about the escalation. I believe this issue is not sufficient to be a valid duplicate, since it doesn't identify the root cause (why there would be 1-2 wei less?), doesn't identify a medium severity impact (functionality DOS by itself is not medium), and doesn't have a valid vulnerability or attack path.

The report doesn't qualify for the Duplication Requirements

The decision remains the same, planning to reject the escalation and de-dup this issue in case #299 becomes valid.

[WangSecurity]

Result:
Invalid
Unique

[sherlock-admin4]

Escalations have been resolved successfully!

Escalation status:

• Senya123: rejected