CVE-2023-34062
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 Reactor Netty HTTP Server, versions 1.1.x prior to 1.1.13 and versions 1.0.x prior to 1.0.39, a malicious user can send a request using a specially crafted URL that can lead to a directory traversal attack. Specifically, an application is vulnerable if Reactor Netty HTTP Server is configured to serve static resources.
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 confidenceDirectory traversal vulnerability in Reactor Netty HTTP Server allows attackers to access files outside the intended static resource directory using specially crafted URLs containing path traversal sequences (e.g., '../'). This only affects applications configured to serve static resources.
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>= 1.0.0, < 1.0.39>= 1.1.0, < 1.1.13CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 Reactor Netty version in your projectCheck your build configuration file (pom.xml for Maven or build.gradle for Gradle) for the reactor-netty dependency and its version. Alternatively, run 'mvn dependency:tree | grep reactor-netty' or 'gradle dependencies | grep reactor-netty' to list the resolved version.Affected if The version listed is >= 1.0.0 and < 1.0.39, OR >= 1.0.0 and < 1.0.39, OR >= 1.1.0 and < 1.1.13, meaning it falls within the vulnerable version ranges.
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Confirm static resource serving is enabledSearch your application codebase for configurations that enable static resource serving via Reactor Netty, such as HttpServer routes with 'FileSystemResource' or 'ClassPathResource', or any route serving files from the filesystem. Look for code using 'HttpServer.route()' with handlers like 'ResourceHandler' or similar.Affected if Your application is configured to serve static files (HTML, CSS, JS, images, etc.) via Reactor Netty's HTTP server - this is the required condition for the vulnerability to be exploitable.
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Check for path traversal exposureIf static resources are served, review the resource handling code to verify whether input validation or path normalization is applied to URL paths before accessing files. Look for any code that does not sanitize '../' sequences from incoming request paths.Affected if The static resource handler accepts raw request paths without validating or normalizing them to prevent directory traversal - this means the vulnerability is present in your configuration.
You are affected if your application serves static resources AND uses a Reactor Netty version between 1.0.0-1.0.38 or 1.1.0-1.1.12, without additional path validation in place.
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 · scoped1.0.391.1.13
Upgrade Reactor Netty to version 1.1.13+ (for 1.1.x) or 1.0.39+ (for 1.0.x) to obtain the security fix.
Reactor Netty 1.0.39 (for 1.0.x users) or Reactor Netty 1.1.13 (for 1.1.x users)
- Identify the current Reactor Netty version in your project (check pom.xml, build.gradle, or dependencies)
- For projects using 1.0.x branch: upgrade Reactor Netty to version 1.0.39 or later
- For projects using 1.1.x branch: upgrade Reactor Netty to version 1.1.13 or later
- After upgrading, verify the application compiles and passes all tests
- Restart the application and confirm static resource serving still works correctly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-34062 — 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-2023-34062 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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