TomcatWeb server / proxy · Apache
CVE-2017-5650
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 Apache Tomcat 9.0.0.M1 to 9.0.0.M18 and 8.5.0 to 8.5.12, the handling of an HTTP/2 GOAWAY frame for a connection did not close streams associated with that connection that were currently waiting for a WINDOW_UPDATE before allowing the application to write more data. These waiting streams each consumed a thread. A malicious client could therefore construct a series of HTTP/2 requests that would consume all available processing threads.
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 9.0.0.M1-9.0.0.M18 and 8.5.0-8.5.12, HTTP/2 GOAWAY frame handling fails to close streams waiting for WINDOW_UPDATE before allowing new data. These waiting streams consume threads, allowing a remote attacker to exhaust all available processing threads via a series of crafted HTTP/2 requests.
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
= 8.5.0= 8.5.1= 8.5.2= 8.5.3= 8.5.4= 8.5.5= 8.5.6= 8.5.7= 8.5.8= 8.5.9= 8.5.10= 8.5.11CVSS 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:3.0/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 versionCheck the Tomcat release notes or run the version.sh (Linux) or version.bat (Windows) script in the Tomcat bin directory. Alternatively, inspect the MANIFEST.MF file inside the catalina.jar located in the lib folder.Affected if The installed version is 8.5.0 through 8.5.12 inclusive.
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Locate server.xml configuration fileFind the server.xml file, typically located in the conf directory of your Tomcat installation.Affected if server.xml exists and contains connector configurations.
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Check for HTTP/2 protocol configurationExamine server.xml for connector elements that specify protocol="HTTP/2" or protocol="org.apache.coyote.http2.Http2Protocol", or look for upgradeProtocol elements referencing HTTP/2.Affected if Any connector is configured to use HTTP/2 protocol.
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Verify HTTP/2 is actually in useReview Tomcat access logs and runtime configuration to confirm HTTP/2 connections are being accepted. Check if the server is binding to HTTP/2 ports (typically 8443 for HTTPS).Affected if HTTP/2 connectors are active and processing requests.
You are affected if your Tomcat version is 8.5.0 through 8.5.12 AND you have HTTP/2 protocol enabled on any connector.
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 dataUpgrade to Apache Tomcat 9.0.0.M19+, 8.5.13+, or later patched versions to resolve the HTTP/2 stream handling flaw. Consider implementing HTTP/2 connection limits and thread pool monitoring as additional defenses.
Fix this in Tomcat
Scoped from the published advisory
- Consultation3.0 h
- Implementation3.0 h
- Testing3.0 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 $3,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-5650 — 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-2017-5650 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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