UndertowApplication · Redhat
CVE-2023-3223
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 · uneditedA flaw was found in undertow. Servlets annotated with @MultipartConfig may cause an OutOfMemoryError due to large multipart content. This may allow unauthorized users to cause remote Denial of Service (DoS) attack. If the server uses fileSizeThreshold to limit the file size, it's possible to bypass the limit by setting the file name in the request to null.
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 confidenceIn undertow, servlets annotated with @MultipartConfig improperly handle large multipart form data, causing OutOfMemoryError that can lead to remote DoS. Additionally, the fileSizeThreshold protection can be bypassed by setting the filename parameter to null in the multipart request, allowing unlimited file uploads despite configured limits.
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
UndertowApplication
< 2.2.24
Openshift Container PlatformApplication
= 4.11= 4.12
Openshift Container Platform For Ibm LinuxoneApplication
= 4.9= 4.10
Openshift Container Platform For PowerApplication
= 4.9= 4.10
Jboss Enterprise Application Platform Text Only AdvisoriesApplication
all versions
Single Sign OnApplication
all versions= 7.6
Jboss Enterprise Application PlatformApplication
= 7.4CVSS 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
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify Undertow deploymentLocate undertow-core.jar or undertow-servlet.jar in your application deployment directory, or check for undertow dependency in pom.xml or build.gradleAffected if Undertow JAR files or dependencies are present in the deployment
-
Check Undertow versionInspect the Undertow JAR manifest (META-INF/MANIFEST.MF) for the Implementation-Version, or check the version in your build configuration (pom.xml, build.gradle)Affected if The installed version is less than 2.2.24
-
Verify @MultipartConfig usageSearch your codebase for servlet classes annotated with @javax.servlet.annotation.MultipartConfig, or check web.xml for <multipart-config> elementsAffected if Servlets with @MultipartConfig annotation or multipart-config are defined in the application
-
Confirm multipart form data processing is enabledReview your servlet or application configuration to confirm multipart form data uploads are being processed; check if file uploads are a functional requirementAffected if The application processes multipart form data uploads from users or clients
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Check fileSizeThreshold configurationInspect the servlet @MultipartConfig annotation parameters (fileSizeThreshold, maxFileSize, maxRequestSize) or the equivalent web.xml multipart-config settingsAffected if fileSizeThreshold is configured but may accept null filename values in multipart requests without validation
You are affected if your environment uses Undertow with @MultipartConfig servlets, the Undertow version is below 2.2.24, and your application processes multipart form data uploads that could be exploited via large requests or null filename bypass.
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 · scoped2.2.24
Implement request size limits at the server or reverse proxy level before undertow processes the multipart content, and validate that fileSizeThreshold cannot be bypassed via null filename values.
Undertow 2.2.24 or later (or equivalent patched version for JBoss EAP/OCP)
- Identify the Undertow dependency in your project (typically via jboss-undertow or wildfly-undertow artifacts)
- Upgrade Undertow to version 2.2.24 or later in your dependency management
- For JBoss EAP deployments, apply the appropriate RHSA patch from access.redhat.com for your version
- For OpenShift Container Platform deployments, apply the corresponding security update for your OCP version (4.9, 4.10, 4.11, or 4.12)
- Rebuild and redeploy applications that use @MultipartConfig servlets
- Verify the OutOfMemoryError issue is resolved by testing with large multipart requests
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Undertow
Scoped from the published advisory
- 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-2023-3223 — 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-2023-3223 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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