TomcatWeb server / proxy · Apache
CVE-2024-34750
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 · uneditedImproper Handling of Exceptional Conditions, Uncontrolled Resource Consumption vulnerability in Apache Tomcat. When processing an HTTP/2 stream, Tomcat did not handle some cases of excessive HTTP headers correctly. This led to a miscounting of active HTTP/2 streams which in turn led to the use of an incorrect infinite timeout which allowed connections to remain open which should have been closed. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.0-M20, from 10.1.0-M1 through 10.1.24, from 9.0.0-M1 through 9.0.89. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M21, 10.1.25 or 9.0.90, which fixes the issue.
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 Apache Tomcat, when processing HTTP/2 streams with excessive HTTP headers, the server incorrectly counted active streams. This miscount led to an incorrect infinite timeout being applied, causing connections that should have been terminated to remain open indefinitely, resulting in uncontrolled resource consumption and potential 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
TomcatWeb server / proxy
>= 9.0.0, < 9.0.90>= 10.1.0, < 10.1.25= 11.0.0= 9CVSS 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 Apache Tomcat installation and versionCheck for Tomcat installation directories and examine the release notes or version file (such as RELEASE-NOTES or the version.jar). Common locations include /opt/tomcat, /usr/share/tomcat, or C:\Program Files\Apache Software Foundation\Tomcat. The version is typically visible in the server startup output or in the RELEASE-NOTES file within the Tomcat home directory.Affected if The installed version falls within 9.0.0 to 9.0.89, 10.1.0 to 10.1.24, or is exactly 11.0.0.
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Determine if HTTP/2 connector is enabledExamine the server.xml configuration file (typically located in the conf/ directory of the Tomcat installation). Look for an <Connector> element with protocol="org.apache.coyote.http2.Http2Protocol" or check for upgradeProtocol="HTTP/2" attribute. This can also be identified by reviewing the startup logs for HTTP/2 initialization messages.Affected if HTTP/2 protocol support is enabled on at least one connector in the Tomcat configuration.
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Check for stuck or lingering HTTP/2 connectionsMonitor active connections using operating system tools (such as netstat or ss on Linux, or netstat on Windows) targeting the Tomcat listener port. Look for connections in established state that persist for an unusually long time, particularly connections that should have timed out based on configured timeout settings.Affected if There are HTTP/2 connections that remain in an established state indefinitely beyond the expected timeout period, indicating the connection leak condition.
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Review Tomcat access logs for incomplete requestsExamine the localhost_access_log or access logs in the logs/ directory. Look for HTTP/2 stream requests with excessive headers that may appear incomplete or show abnormal timing patterns. Correlate these with the connection states observed.Affected if Access logs show HTTP/2 requests with large header counts that never complete or show abnormal connection duration patterns.
A system is affected if it runs a vulnerable Apache Tomcat version (9.0.0-9.0.89, 10.1.0-10.1.24, or 11.0.0) with HTTP/2 protocol enabled and exhibits connections that remain open indefinitely beyond configured timeouts.
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 · scoped9.0.9010.1.25
Upgrade Apache Tomcat to version 11.0.0-M21, 10.1.25, or 9.0.90 to patch the improper HTTP/2 stream handling that causes connection leaks.
9.0.90 for 9.x branch, 10.1.25 for 10.1.x branch, or 11.0.0-M21 for 11.x branch
- 1. Identify the currently running Tomcat version by checking the $CATALINA_HOME/README RELEASE-NOTES or running 'catalina.sh version'
- 2. Stop the Tomcat service/application
- 3. Download the appropriate fixed Tomcat version from the official Apache Tomcat download page (https://tomcat.apache.org/)
- 4. For Tomcat 9.x users: upgrade to version 9.0.90
- 5. For Tomcat 10.1.x users: upgrade to version 10.1.25
- 6. For Tomcat 11.x users: upgrade to version 11.0.0-M21
- 7. Backup the existing Tomcat installation and configuration files
- 8. Extract the new version and restore custom configurations from the backup
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Tomcat
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-34750 — 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-2024-34750 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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