CVE-2019-16535
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 · uneditedIn all versions of ClickHouse before 19.14, an OOB read, OOB write and integer underflow in decompression algorithms can be used to achieve RCE or DoS via native protocol.
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 confidenceClickHouse versions before 19.14 contain multiple memory safety vulnerabilities (OOB read, OOB write, integer underflow) in decompression algorithms used by the native protocol, allowing remote attackers to achieve code execution or cause denial of service.
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< 19.14CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
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Check installed ClickHouse versionRun 'clickhouse-server --version' or query the system table: SELECT version()Affected if Version number is less than 19.14 (e.g., 19.13.x, 19.12.x, etc.)
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Verify native protocol is enabledInspect ClickHouse config.xml for <listen_host> settings and check if the native protocol port (9000) is boundAffected if Native protocol is listening on an accessible network interface (0.0.0.0 or externally reachable IP)
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Confirm native protocol port accessibilityRun 'netstat -tlnp | grep 9000' or 'ss -tlnp | grep 9000' to verify port 9000 is open and listeningAffected if Port 9000 is in LISTEN state and accessible from untrusted networks
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Check for unencrypted native protocol exposureReview firewall rules and network configuration to determine if port 9000 is exposed to the internet or untrusted networksAffected if Native protocol port 9000 is reachable without firewall restrictions from external hosts
A user is affected if ClickHouse version is below 19.14 AND the native protocol (port 9000) is accessible to remote attackers.
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.
dbcve · scoped19.14
Upgrade ClickHouse to version 19.14 or later. If immediate upgrade is not possible, restrict network access to the native protocol port (9000 by default) using firewall rules or network segmentation.
19.14
- 1. Backup your ClickHouse data and configuration files before upgrading.
- 2. Stop the ClickHouse server.
- 3. Upgrade ClickHouse to version 19.14 or later.
- 4. Verify the installation and configuration integrity.
- 5. Restart the ClickHouse server.
- 6. Test that queries and the native protocol function correctly.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-16535 — 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-2019-16535 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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- 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
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