Summary: When a security audit fails two weeks before a go‑live or a procurement review, the fastest path to ROI isn’t a rewrite—it’s a disciplined remediation sprint that fixes root causes, proves safety with evidence, and unblocks SOC 2/ISO 27001 and vendor due‑diligence checklists. Below is exactly how 7Block executes a 14‑day “Remediation Sprint” that closes Solidity and ZK gaps, aligns to Enterprise change‑management controls, and gets you to “ship” without gambling on production.

How 7Block Conducts a “Remediation Sprint” After a Failed Audit

Audience: Enterprise leaders owning delivery dates, SOC 2, vendor risk, and budget accountability.

Pain — The concrete headache you’re feeling today

• Your audit flagged High/Critical issues across upgradeability, circuit constraints, or key‑management. You’re staring at missed Q targets, blocked procurement, and a stalled GTM.
• Ethereum changes like EIP‑6780 (SELFDESTRUCT semantics), EIP‑7623 (calldata floor pricing), and EIP‑7702 (EOA “Set Code”) shifted assumptions many codebases still rely on; upgrade plans, cost models, and wallet logic can quietly break. (eips.ethereum.org)
• If ZK is in scope, unconstrained signals or verifier/key mismatches can pass proofs that shouldn’t—fail audit today, become an incident tomorrow. Circom now warns on under‑constrained signals; the “<-- vs <== / ===” mix‑up is a repeat offender in real reports. (docs.circom.io)
• Meanwhile, your board just asked “what’s the plan for SOC 2/ISO 27001 evidence?” New ISO/IEC 27001:2022 consolidates controls and adds A.8.28 Secure coding—your dev/change controls and remediation evidence must map cleanly. (dqsglobal.com)

Agitation — What happens if you wait

• Deadlines slip; partner procurement stalls on SIG‑Lite/SIG‑Core due‑diligence; renewals are at risk because “High” findings remain open. Shared Assessments’ SIG is increasingly standard in vendor risk workflows and directly maps to frameworks your customers care about. (sharedassessments.org)
• Cost blow‑ups: data‑heavy transactions priced under pre‑Pectra assumptions miss gas budgets after EIP‑7623’s calldata floor; ZK proof verifiers that didn’t plan for BLS12‑381 precompiles leave performance on the table or force contract changes late in the cycle. (eips.ethereum.org)
• Breach and brand risk: 2025 saw ~$3.4B in crypto thefts with “big‑game” incidents driving 69% of service losses—security debt concentrates tail risk into single, business‑ending events. Your board won’t accept “we’ll patch post‑launch.” (chainalysis.com)

Solution — 7Block’s 14‑Day Remediation Sprint (technical but pragmatic)

We run a structured, evidence‑driven sprint that closes critical defects, proves fixes with property tests/formal checks, and ships the artifacts your auditor and procurement want. You keep momentum; we keep you honest.

Day 0–2: Rapid triage, severity alignment, and blast‑radius mapping

• Confirm/replicate every “High/Critical” with deterministic tests:
  • Foundry unit + invariant scaffolding; fuzz harnesses configured with profiles for max runs, plus handler‑based invariants where needed. (docfork.com)
  • Slither static analysis for reentrancy, dangerous delegatecall, uninitialized storage, and custom detectors for your patterns. (github.com)
  • Echidna property‑based fuzzing for edge‑case discovery; for large systems we federate properties via Chimera so one property runs across Foundry/Echidna/Medusa/Halmos. (medium.com)
• Align severities with your auditor’s taxonomy (Critical/High/Medium/Low/Info/Gas) to avoid reclassification churn during fix review. (rareskills.io)
• Hardfork/regulatory deltas checklist:
  • EIP‑6780—audit any SELFDESTRUCT‑based cleanup in upgradables. It no longer deletes code/storage except in “create‑and‑destroy‑same‑tx”; migration/kill‑switch patterns must change. (eips.ethereum.org)
  • EIP‑7623—re‑baseline calldata‑heavy flows; enforce floors in gas estimation to prevent user tx underpricing. (eips.ethereum.org)
  • EIP‑7702—if wallets or access control assume tx.origin invariants, flag for remediation; delegate‑based EOAs change execution paths and replay/nonce assumptions. (eips.ethereum.org)
• Procurement prep: establish evidence threads for SOC 2 CC8 (change management), CC6/CC7 (access/operations), ISO 27001 A.8.28 (secure coding), and NIST SSDF PR/PO/PW tasks. We start the binder on Day 1. (aicpa-cima.com)

Day 2–5: Patch design for Solidity, ZK, and wallets—without rewriting your product

• Upgradeability and storage layout:
  • Use OpenZeppelin Upgrades validation to block storage collisions, enforce “gap” patterns, and validate UUPS/Transparent proxy safety in CI. We wire the validate/validateUpgrade steps into your pipeline. (docs.openzeppelin.com)
  • Remove SELFDESTRUCT‑dependent flows; design explicit pause/withdraw/escape hatches; update runbooks accordingly. (eips.ethereum.org)
• ZK circuits and verifiers:
  • Run circom --inspect to surface under‑constrained signals; replace unsafe “<--” assignments with “<==/===” constraints and add non‑linear ties for public inputs so they can’t be optimized away. (docs.circom.io)
  • If you’re on BN254 Groth16, document the on‑chain cost profile (pairing base + per‑pair cost per EIP‑1108) and decide whether to migrate proofs to BLS12‑381 to use Pectra’s precompiles (trade: cheaper pairings/MSM precompile vs larger calldata). We model both paths. (eips.ethereum.org)
• Wallet and account model:
  • Harden against EIP‑7702 pitfalls: signature domain separation, nonce/replay scopes, no tx.origin checks, and explicit delegation revocation flows; add invariant tests for “delegation cannot widen permissions.” (eips.ethereum.org)

Day 5–7: Prove the fixes can’t regress

• Formal checks with Solidity’s SMTChecker: configure CHC engine with z3/cvc5 targets, set explicit invariants (e.g., “totalAssets never decreases except by withdrawals,” “no external call during state‑mutating critical section”), and export proved targets/unproved targets into the evidence binder. (docs.soliditylang.org)
• Property tests: encode protocol‑level invariants (e.g., conservation of value, authz lattices) in Foundry/Halmos and long‑run fuzz in Echidna. We snapshot crashing seeds as regression tests. (medium.com)
• ZK verification: regenerate vk/proof test vectors, and re‑emit Verifier.sol from snarkjs/Barretenberg where relevant; add tests that flip single bits in proof or public inputs to ensure rejection. (docs.circom.io)

Day 7–10: Implement, retest, and gas/profile

• Code patches with isolated PRs per finding; Foundry “invariants” profile and gas snapshots to ensure no new foot‑guns and that cost deltas are explainable and acceptable post‑EIP‑7623. (docfork.com)
• If ZK on Ethereum:
  • BN254 verifier: confirm pairing count/gas against EIP‑1108 (34k per pairing + 45k base) and MSM cost per public input; document “per‑proof” gas for procurement and finance. (eips.ethereum.org)
  • BLS12‑381 verifier: confirm precompile availability under Pectra and re‑baseline pairing/MSM costs; include calldata impact and any SIGNED‑BY proof size changes in your business case. (blog.ethereum.org)
• Dry‑runs: deploy to Holesky/Sepolia with mainnet‑fork tests for realistic interfaces/events; include upgrade rehearsals with Safe‑based approvals and timelocks, capturing screenshots/logs for SOC 2 evidence. (blog.ethereum.org)

Day 10–12: Auditor and Procurement “Fix Review” pack

• We produce a single “Fix Review” binder your auditor can consume in hours, not weeks:
  • Diff‑by‑PR per issue, tests proving reproduction and fix, Slither/Echidna/Foundry outputs, SMTChecker proof summaries, and risk acceptance (if any) with compensating controls.
  • Mapping matrix: each code/config change mapped to SOC 2 CC8 (change management), CC7 (monitoring), ISO 27001 A.8.28 (secure coding) and SSDF tasks (PO/PS/PW). (aicpa-cima.com)
• If your customers require SIG‑Lite/SIG‑Core packages, we pre‑populate relevant responses and attach evidence artifacts so Sales/BD isn’t blocked waiting on engineering. (sharedassessments.org)

Day 12–14: Production readiness, runbooks, and post‑merge monitoring

• Upgrade ceremony: Proxy admin checks, OpenZeppelin storage validation in CI, Safe multisig thresholds, emergency pause runbooks, and post‑upgrade assertions.
• Runtime guardrails:
  • Chain‑aware alerting on reverts/gas spikes after EIP‑7623; watch for unexpected calldata composition changes from integrators. (eips.ethereum.org)
  • Wallet delegation monitors for EIP‑7702 adoption spikes and potential phishing patterns per ecosystem guidance. (frameworks.securityalliance.org)
• Supply‑chain hardening for procurement: implement Sigstore/Cosign signing in CI for containerized off‑chain components; Rekor‑logged attestations give you a tamper‑evident trail that satisfies modern “secure by design” expectations and audit traceability. (github.blog)

Practical examples (with exact, current details)

1. Upgradeable contract fails storage check during fix review

• Problem: Adding a uint256 in a base contract shifted inherited storage; OZ Upgrades flagged a collision.
• Fix: Introduced __gap[] in base contracts and re‑ran oz upgrades validate; storage diff cleared; CI blocks any upgrade with unsafe layout deltas. We also removed a legacy SELFDESTRUCT unlock step per EIP‑6780. (openzeppelin.com)
• Outcome: Auditor reclassified the issue to “Resolved”; upgrade rehearsal recorded for SOC 2 CC8 evidence. (aicpa-cima.com)

1. Circom circuit accepted invalid proofs under edge conditions

• Problem: Developer used “<--” with no accompanying constraint; public input wasn’t tied to any non‑linear constraint and could be optimized out.
• Fix: Replaced with “<==/===” and added a non‑linear tie (e.g., c_sq <== c * c). Ran circom --inspect to verify no under‑constrained signals remained; added proof‑bit‑flip tests. (docs.circom.io)
• Outcome: Fix verified; Solidity verifier regenerated; on‑chain verification now rejects single‑bit perturbations of inputs/proofs. (docs.circom.io)

1. Gas budget mismatch after Pectra/EIP‑7623

• Problem: Batch calls that relied on calldata‑heavy patterns began exceeding gas caps under the new floor pricing; dashboards didn’t flag it pre‑launch.
• Fix: Modeled calldata/gas with EIP‑7623’s floor; moved data to blobs or compressed calldata where DA wasn’t needed; for ZK, we rebased from BN254 to BLS12‑381 to leverage pairing/MSM precompiles where net gas made sense for the public‑input profile. (eips.ethereum.org)
• Outcome: Cost stabilized; finance received a pre/post gas profile and “worst‑case” modeling beyond averages.

1. Wallet/account model drift with EIP‑7702

• Problem: Legacy checks used tx.origin and assumed “one call per tx”; delegation introduced multi‑call paths and replay nuances.
• Fix: Refactored auth to msg.sender + explicit permissions; added domain‑separated signatures and a revocation path; created invariants to prevent delegation from widening permissions; added runbooks for phishing‑style “SetCode” prompts. (eips.ethereum.org)

What we deliver (and why it matters to ROI and Procurement)

• Engineering artifacts
  • Fix PRs per finding, reproducible tests (unit, fuzz, invariant), Slither/Echidna outputs, and SMTChecker summaries. (github.com)
  • ZK artifacts: regenerated vk/proofs, regenerated Verifier.sol, and gas/cost profile under current EIPs. (docs.circom.io)
• Compliance and vendor‑risk artifacts
  • SOC 2/ISO 27001 mapping and evidence binder aligned to CC8, CC7, CC6, and A.8.28, plus NIST SSDF reference table for secure SDLC posture. (aicpa-cima.com)
  • SIG‑Lite/SIG‑Core response package with links to signed build attestations (Sigstore/Rekor) for off‑chain components. (sharedassessments.org)

GTM metrics we use to prove success (what your CFO, CISO, and Sales care about)

• “Money phrases” we target:
  • Reduced “time‑to‑fix‑review” (auditor turnaround) to days, not weeks, by shipping isolated PRs, proofs, and a single binder that answers severity, fix, and test evidence in one pass.
  • Faster procurement clearance via pre‑built SOC 2/ISO 27001 mapping and SIG‑Lite/SIG‑Core responses—no back‑and‑forth for screenshots later.
  • Predictable operating cost post‑EIP‑7623 with explicit calldata floors and ZK pairing/MSM modeling; no post‑launch surprises in gas per call. (eips.ethereum.org)
• Execution SLAs (typical pilot commitments):
  • <48–72h to land fixes for all High/Criticals reproducible in tests.
  • 100% of upgradable storage changes validated by OZ in CI; no “unsafeSkipStorageCheck” ever in production pipelines. (docs.openzeppelin.com)
  • ZK verifiers: proofs regenerated + bit‑flip rejection tests; verifier gas profiled under current EIPs.

Tooling stack we standardize (so your team can sustain the fixes)

• Solidity: Foundry (forge/anvil/cast), Slither, Echidna, SMTChecker, and OpenZeppelin Upgrades validation—wired into CI with fail‑fast gates. (docfork.com)
• ZK: Circom/snarkjs or Noir/Barretenberg with --inspect and constraint‑safety checks; on‑chain verification tuned for BN254 (EIP‑1108) or BLS12‑381 (EIP‑2537) depending on cost/security needs. (docs.circom.io)
• Supply chain: Sigstore/Cosign signing + Rekor attestations for containerized services to satisfy secure‑by‑design expectations and audit trails. (github.blog)

Where 7Block fits into your roadmap (and how to engage)

• If you need hands‑on remediation and re‑audit in the next two weeks, we slot in as an extension of your team and own the “fix + proof + evidence” loop end‑to‑end.
• If you want to institutionalize this (to avoid repeating it next quarter), we transition you to our ongoing [security audit services] and [blockchain integration] programs with guardrails embedded into CI/CD and procurement workflows:
  • Our [security audit services] focus on pre‑audit hardening and fix‑review packages to minimize churn with your chosen auditor.
  • Our [blockchain integration] program ensures EIP changes, ZK proof systems, and wallet standards don’t surprise your product teams again.
• For projects that require additional delivery capacity (e.g., refactors, protocol expansions), our [blockchain development services] and [web3 development services] teams can parallelize workstreams while the remediation sprint unblocks launch.

Internal links you can use right now

• Need help shipping fixes? See our custom security audit services.
• Need engineers to implement upgrades/patches fast? Our blockchain development services and web3 development services deliver production code, not reports.
• Integrating new EIPs, wallets, or ZK verifiers into your stack? Engage our blockchain integration team.
• Building a new secure dApp or DeFi component alongside remediation? Our dApp development and smart contract development teams can run in parallel.

Why this works

• It’s not just vulnerability fixes—it’s a method that marries fix correctness (tests/proofs) with compliance evidence (SOC 2/ISO 27001/NIST SSDF/SIG) and current‑network realities (EIPs, precompiles, calldata pricing). That’s what unblocks both engineering and procurement in the same sprint. (aicpa-cima.com)

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