CVE-2024-3653
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 vulnerability was found in Undertow. This issue requires enabling the learning-push handler in the server's config, which is disabled by default, leaving the maxAge config in the handler unconfigured. The default is -1, which makes the handler vulnerable. If someone overwrites that config, the server is not subject to the attack. The attacker needs to be able to reach the server with a normal HTTP request.
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 confidenceIn Undertow, the learning-push handler (disabled by default) has an insecure default value for the maxAge configuration parameter (-1). When this handler is enabled without explicitly configuring maxAge, the server becomes vulnerable to attack via normal HTTP requests.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 installationDetermine if the target system uses Undertow as its web server. Undertow is commonly embedded in JBoss/WildFly, Keycloak, or other Java applications. Check for undertow-core JAR files or Undertow subsystem in JBoss configuration files.Affected if Undertow is present in the environment
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Locate Undertow configurationFind the Undertow configuration file. In JBoss/WildFly, this is typically standalone.xml or domain.xml under the undertow subsystem. For embedded Undertow, check application configuration or programmatic setup files.Affected if A configuration file containing Undertow settings is found
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Check if learning-push handler is enabledSearch the configuration for 'learning-push' handler entries. Look for handler definitions within the undertow subsystem or Undertow configuration that enable this feature.Affected if The learning-push handler is explicitly configured and enabled
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Inspect maxAge parameter valueExamine the learning-push handler configuration for the maxAge attribute. Verify whether maxAge is set to -1, unset, or set to a positive integer value.Affected if The learning-push handler is enabled and maxAge is either set to -1 or not explicitly configured to a positive value
The environment is affected if Undertow is in use, the learning-push handler is enabled, and the maxAge parameter is set to -1 or left at its default value.
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 dataExplicitly configure the maxAge parameter in the learning-push handler to a positive value (not -1), or ensure the learning-push handler remains disabled if not required.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2024-3653 — 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-2024-3653 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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