Smart Contract Audit Remediation & Fixes

A security firm has sent you a report. It carries severity labels, file references, and a line somewhere that says a finding must be fixed before deployment. Your team wrote the contracts, or inherited them from someone else, and now has to work out which findings can actually be exploited, what each fix costs in gas and in changed behaviour, and how to prove the fix holds. That gap between a report and a deployable contract is where most smart contract audit remediation work stalls.

We take an existing audit report and close it out. We read the findings, reproduce them against the real code, rank them by exploitability and business impact, patch the contracts, and add tests that fail on the old code and pass on the new one. Then we help you prepare a mainnet release with deployment and upgrade procedures that match the contracts you are shipping.

The scope is narrow by design. This is remediation of an existing report, so it does not replace an independent audit, and patched code is not the same as verified code. What we can show you is each finding reproduced, the change that addresses it, and the test that covers it. For contracts that hold significant value, we still recommend an independent review of the changed code before deployment.

What an audit report leaves you with

Audit reports are written for several audiences at once. Severity ratings do not always map to your product: a medium issue in a function you never call in production can matter less than a low issue in the withdrawal path that moves customer funds. Reports also describe the problem rather than the patch, so your team still has to design the change, keep the rest of the system working, and re-run everything that depends on the contract.

Situations that bring teams to us:

• A pre-launch audit returned findings and the release date is close.
• Part of the report was addressed, with some findings acknowledged but left unfixed.
• Contracts changed after the audit, so the report no longer describes the deployed code.
• An upgrade or proxy change invalidated assumptions from earlier review.

Who smart contract audit remediation is for

This service fits teams with a written audit already in hand: a protocol preparing a first mainnet deployment, a token team whose launch is blocked by an unresolved finding, an exchange or payment product with contract code under review, or a founder who inherited contracts and needs a straight read on what the report really requires. If you do not have an audit yet, start with our smart contracts development page, which covers writing contracts and preparing them for review.

What we deliver

A triage of the findings

We go through the report line by line, reproduce each issue in a local environment, and classify it by exploitability, the position an attacker needs to hold, and the impact on funds or user data. The output is a prioritised list that separates what blocks a mainnet release from what can be scheduled later, with reasoning you can share with your own team and with your auditor.

Patched contract code

Fixes follow the smallest change that removes the problem while preserving the contract's intended behaviour. Where a fix changes storage layout, event signatures, or external interfaces, we document that explicitly, because those changes reach integrations, indexers, and frontends.

Tests that prove the fix

For each remediated finding we add a test that fails against the vulnerable revision and passes after the patch. Where a finding depends on chain state or a specific sequence of calls, we reproduce it on a fork instead of a simplified mock. Regression tests stay in the repository so the same issue cannot return unnoticed through a later change.

Upgrade and deployment procedures

On upgradeable contracts we prepare the upgrade path, storage checks, and validation steps. For immutable deployments we prepare the deployment script, the verification steps, and the post-deployment checks that confirm the deployed bytecode behaves as reviewed.

A remediation summary

You get a written record that maps each finding to its status, the change made, and the test covering it. That record is what you hand back for re-review, and it shortens the follow-up because the reviewer can see exactly what moved.

How the engagement runs

Remediation usually runs in phases. The first is triage: we read the report, reproduce the findings, and give you a prioritised plan with an effort estimate for each item. That phase is short, and it often runs before any commitment to the full fix work.

The second is the fix sprint. We patch the contracts, add the failing-then-passing tests, and keep a running note of any finding that cannot be settled by a code change alone. Some findings cannot be removed in code, such as a centralisation risk in an admin role or a dependency on an external price feed. Those become documented accepted risks with the mitigation and monitoring we recommend.

The third is re-review and release preparation. Depending on the finding set, we prepare the changed code for a follow-up review by the original firm or another one, then run the deployment script against a testnet, verify the contracts, and hand over the runbook for mainnet. Most engagements fit inside one to four weeks of engineering time, and a protocol with several interacting contracts takes longer.

Where remediation touches an operator dashboard or admin panel, that work sits alongside our custom web application development so the tooling matches the new contract interfaces.

What it costs

Remediation is quoted at our flat rate of $39 per hour, or as a fixed scope once we have read the report and reproduced the findings. A single contract with a handful of findings is a short piece of work. A multi-contract protocol with access control, upgrade logic, and external integrations is a longer engagement that we plan in phases.

Scope drivers are the number of findings that require code changes, whether a test suite already exists, whether the contracts are upgradeable, how many chains you deploy to, and how much of the finding set needs design work beyond a straightforward patch. Teams that expect steady contract work after the fix can use a monthly capacity plan from $2,699, which keeps the same engineers on your codebase. The pricing page explains both models and what each one suits.

Proof

Send Crypto is a payment product on Polygon with public Solidity contracts. A formal audit dated 24 October 2022 produced findings, and the case study documents the contract refinements that followed, including the hardening work the project needed after review. It shows we have followed an audit report through to changed, redeployed code.

NFTTRX is an NFT platform where the ownership and copyright logic sits in a smart contract under public, immutable conditions. That is the same constraint that makes remediation work worth doing carefully, because ownership errors are visible and permanent once deployed.

Garantex Exchange is a cryptocurrency exchange built on the open-source Peatio framework, with two-factor authentication and KYC/AML procedures. It shows we have worked inside financial systems where an access control or settlement defect is expensive, and where the release process needs to be documented.

Related services

• Smart Contracts Development for writing and preparing contracts before an audit
• Solidity Smart Contract Developer for focused Solidity engineering work
• dApps Development for the frontend, wallet, and indexing layer around the contracts
• Fintech and Web3 Development for products that sit between blockchain and traditional finance
• Crypto Payments and Automated Reward Contracts for payment and reward distribution logic, where audit findings often land hardest

Next step

Send us the audit report and read access to the repository. We will come back with a triage note that names which findings block your release, which can wait, and what the fix work involves.

Contact us with the report attached, or run the scope through the Vasilkoff.info estimator if you want a first cost range before the conversation.