dbcve.org
Go EthereumApplication · Ethereum

CVE-2021-43668

MEDIUM · 5.5 CVSS v3.1 Published 2021-11-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
57/100
Remediation priority · Elevated
Zero-click

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
Go-Ethereum 1.10.9 nodes crash (denial of service) after receiving a serial of messages and cannot be recovered. They will crash with "runtime error: invalid memory address or nil pointer dereference" and arise a SEGV signal.

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 · moderate confidence

Go-Ethereum 1.10.9 nodes suffer from a denial of service vulnerability triggered by receiving a specific series of messages, causing a nil pointer dereference that crashes the node with a SEGV signal. The crash is unrecoverable, requiring manual intervention to restart the affected node.

MitigationUpgrade to a patched version of Go-Ethereum (1.10.10 or later) or implement network-level filtering to block malicious message sequences targeting vulnerable nodes.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
Go EthereumApplication
Affected:= 1.10.9

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Go-Ethereum version
    Run 'geth version' or check the binary version information. If using a package manager, query the installed package version.
    Affected if The installed version is exactly 1.10.9 (no other versions are affected)
  2. Verify node is running and responsive
    Attempt to connect to the node via RPC (e.g., curl to HTTP endpoint) or check if the process is alive using system commands like 'ps aux | grep geth'.
    Affected if The node has crashed and is unresponsive, which may indicate this vulnerability was triggered
  3. Check for recent crash logs or SEGV signals
    Review node logs for 'SEGV', 'nil pointer', or 'signal 11' entries. On Linux, check 'dmesg' or system journal for crash reports.
    Affected if Logs show a SEGV crash with nil pointer dereference pattern matching the CVE description
  4. Confirm network exposure
    Verify the node has active P2P connections (check enode URL, peer count via 'admin.peers' RPC call, or network listening ports).
    Affected if The node has open P2P ports and is connected to other peers, making it susceptible to the malicious message sequence

A user is affected if their Go-Ethereum node is version 1.10.9 and has crashed with a SEGV error after receiving malicious P2P messages.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched version of Go-Ethereum (1.10.10 or later) or implement network-level filtering to block malicious message sequences targeting vulnerable nodes.

Recommended fix Moderate confidence

Go Ethereum 1.10.10 or later (recommended: latest stable 1.10.x release)

  1. 1. Stop the Go Ethereum 1.10.9 node service safely
  2. 2. Backup the node data directory and configuration files
  3. 3. Download Go Ethereum version 1.10.10 or later from the official repository (github.com/ethereum/go-ethereum/releases)
  4. 4. Verify the SHA256 checksum of the downloaded binary before installation
  5. 5. Replace the existing go-ethereum binary with the new version
  6. 6. Restart the Go Ethereum node service
  7. 7. Monitor logs for the first few minutes to ensure stable operation
Caveat Minor version upgrades in Go Ethereum typically maintain chain compatibility; however, verify release notes for any consensus changes or protocol updates before upgrading production nodes

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

Fix this in Go Ethereum Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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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-2021-43668 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data