CVE-2018-20587
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 · uneditedBitcoin Core 0.12.0 through 0.17.1 and Bitcoin Knots 0.12.0 through 0.17.x before 0.17.1.knots20181229 have Incorrect Access Control. Local users can exploit this to steal currency by binding the RPC IPv4 localhost port, and forwarding requests to the IPv6 localhost port.
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 · high confidenceBitcoin Core and Bitcoin Knots have an Incorrect Access Control vulnerability in their RPC interface. Local users can bind to the RPC IPv4 localhost port and forward requests to the IPv6 localhost port, bypassing intended authorization checks and allowing theft of cryptocurrency.
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>= 0.12.0, <= 0.17.1>= 0.12.0, <= 0.17.0CVSS 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
- High
- Availability
- None
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Identify the installed Bitcoin software and versionRun `bitcoind --version` or `bitcoin-cli getnetworkinfo` to determine the exact version number. Compare against the affected range: Bitcoin Core 0.12.0 through 0.17.1, or Bitcoin Knots 0.12.0 through 0.17.0.Affected if The version falls within 0.12.0 to 0.17.1 for Core, or 0.12.0 to 0.17.0 for Knots.
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Confirm RPC interface is enabledCheck the bitcoin.conf file (located in ~/.bitcoin/ on Linux/macOS or %APPDATA%\Bitcoin\ on Windows) for rpcuser and rpcpassword settings, or verify bitcoind was started with RPC flags. Also check for rpcbind or rpcport directives.Affected if RPC authentication is configured and the RPC interface is active.
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Identify RPC port bindingsInspect the configuration for rpcbind settings (e.g., rpcbind=127.0.0.1 or rpcbind=::1). Use `netstat -anp | grep 8332` or equivalent to see which ports bitcoind is listening on. Check if both IPv4 (127.0.0.1:8332) and IPv6 (::1:8332) localhost bindings exist.Affected if The RPC service is bound to both IPv4 and IPv6 localhost addresses, allowing a local untrusted user to potentially forward requests between them.
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Check for multiple RPC port configurationsReview bitcoin.conf for multiple rpcport declarations or rpcbind entries. Examine if separate ports are configured for IPv4 versus IPv6. Look for configurations where the IPv4 and IPv6 bindings point to different authorization states.Affected if The RPC service has distinct IPv4 and IPv6 localhost bindings that can be exploited by a local user to bypass authorization checks.
You are affected if you run a vulnerable version (0.12.0-0.17.1 Core or 0.12.0-0.17.0 Knots) with RPC enabled and both IPv4 and IPv6 localhost bindings configured.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataUpgrade to Bitcoin Core 0.17.2+ or Bitcoin Knots 0.17.1.knots20181229+ to obtain the patched version. Alternatively, ensure RPC ports are not exposed to untrusted local users and consider network isolation.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-20587 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-20587 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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