dbcve.org
TomcatWeb server / proxy · Apache

CVE-2019-0199

HIGH · 7.5 CVSS v3.0 Published 2019-04-10
Fix available
A fix is available. Upgrade to after 9.0.14 or later.
See remediation →
84/100
Remediation priority · High
High EPSS Remotely reachable No privileges Zero-click

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 · unedited
The HTTP/2 implementation in Apache Tomcat 9.0.0.M1 to 9.0.14 and 8.5.0 to 8.5.37 accepted streams with excessive numbers of SETTINGS frames and also permitted clients to keep streams open without reading/writing request/response data. By keeping streams open for requests that utilised the Servlet API's blocking I/O, clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.

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 confidence

Apache Tomcat's HTTP/2 implementation (versions 9.0.0.M1-9.0.14 and 8.5.0-8.5.37) accepted streams with excessive SETTINGS frames and allowed clients to keep streams open without data transfer. This caused thread exhaustion when blocking I/O servlets were used, resulting in DoS.

MitigationUpgrade Apache Tomcat to version 9.0.15 or later (for 9.x) or 8.5.38 or later (for 8.5.x). Alternatively, disable HTTP/2 if not required.

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
Affected:>= 8.5.0, <= 8.5.37>= 9.0.1, <= 9.0.14= 9.0.0

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
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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Apache Tomcat version
    Check the release notes or the version.properties file in the Tomcat installation directory, or run 'java -cp catalina.jar org.apache.catalina.util.ServerInfo'
    Affected if Version is 8.5.0-8.5.37, 9.0.0, or 9.0.1-9.0.14
  2. Confirm HTTP/2 connector is enabled
    Review the server.xml configuration file in the Tomcat conf directory and look for an HTTP/2 connector element (such as <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol"/> inside a Connector)
    Affected if HTTP/2 protocol upgrade is configured on at least one connector
  3. Verify blocking I/O servlet usage
    Inspect deployed web applications and identify if servlets use blocking I/O (synchronous request handling without non-blocking or async servlet configurations)
    Affected if Blocking I/O servlets are handling HTTP/2 requests

A server is affected if it runs a vulnerable Tomcat version (8.5.0-8.5.37 or 9.0.0-9.0.14), has HTTP/2 enabled, and uses blocking I/O servlets that can exhaust threads under load.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to a release after 9.0.14
Interim mitigation

Upgrade Apache Tomcat to version 9.0.15 or later (for 9.x) or 8.5.38 or later (for 8.5.x). Alternatively, disable HTTP/2 if not required.

Fix this in Tomcat Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.

Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-0199 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data