FrontierApplication · Parity

CVE-2022-21685

MEDIUM · 6.5 CVSS v3.1 Published 2022-01-14
Fix available
A fix is available. Upgrade to after 2022-01-13 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Frontier is Substrate's Ethereum compatibility layer. Prior to commit number `8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664`, a bug in Frontier's MODEXP precompile implementation can cause an integer underflow in certain conditions. This will cause a node crash for debug builds. For release builds (and production WebAssembly binaries), the impact is limited as it can only cause a normal EVM out-of-gas. Users who do not use MODEXP precompile in their runtime are not impacted. A patch is available in pull request #549.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FrontierApplication
Affected:<= 2022-01-13

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 2022-01-13
Vendor patch github.com →
Recommended fix High confidence

Commit 8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664 (or later version containing this fix)

  1. Identify the affected Frontier codebase version (prior to commit 8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664)
  2. Navigate to the MODEXP precompile implementation in the Frontier codebase
  3. Apply or cherry-pick the fix from commit 8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664, or update the code to match the changes in that commit
  4. Rebuild the Frontier runtime with the patched code
  5. If using the MODEXP precompile, verify the fix resolves the integer underflow issue
  6. For production deployments, ensure you are using a release build rather than debug build to limit impact to out-of-gas scenarios only
Caveat Minimal - the fix only addresses the bug; users not using MODEXP precompile are not impacted

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-21685 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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