CVE-2020-9040
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 · uneditedCouchbase Server Java SDK before 2.7.1.1 allows a potential attacker to forge an SSL certificate and pose as the intended peer. An attacker can leverage this flaw by crafting a cryptographically valid certificate that will be accepted by Java SDK's Netty component due to missing hostname verification.
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 confidenceThe Couchbase Server Java SDK before version 2.7.1.1 contains a critical SSL/TLS vulnerability in its Netty component. The SDK fails to perform hostname verification, allowing attackers to use cryptographically valid but fraudulent certificates to impersonate legitimate servers. This enables man-in-the-middle attacks where encrypted communication can be intercepted or manipulated.
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>= 1.7.1, < 2.7.1.1CVSS 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
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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 Couchbase Java SDK usageSearch your project dependencies (pom.xml, build.gradle, requirements.txt) or application libraries for 'com.couchbase.client:java-client' or 'couchbase-java-sdk' entriesAffected if The Couchbase Java SDK dependency is present in the application
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Determine installed SDK versionFind the exact version number of the Couchbase Java SDK in your dependency management files or by inspecting the deployed jar file name (e.g., java-client-2.x.x.jar)Affected if The installed version is 1.7.1 or higher but below 2.7.1.1
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Verify SSL/TLS connection is usedInspect your application configuration files and connection code for SSL/TLS enabled settings such as 'sslEnabled=true', 'useSSL=true', or 'couchbases://' scheme in connection stringsAffected if SSL/TLS connections to Couchbase are enabled in the configuration
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Confirm Netty-based transportCheck if your application uses the default Netty I/O transport (this is the default for Couchbase Java SDK 2.x). Look for netty-transport dependencies in your classpathAffected if The application uses the default Netty transport layer for Couchbase connections
Your environment is affected if you use the Couchbase Java SDK versions 1.7.1 through 2.7.1.0 with SSL/TLS enabled and the default Netty transport, allowing man-in-the-middle attackers to intercept encrypted traffic using fraudulent certificates.
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 data2.7.1.1
Upgrade the Couchbase Server Java SDK to version 2.7.1.1 or later, which includes proper hostname verification for SSL/TLS connections.
- Consultation1.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-9040 — 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-2020-9040 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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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.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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