dbcve.org
TomcatWeb server / proxy · Apache

CVE-2023-28709

HIGH · 7.5 CVSS v3.1 Published 2023-05-22
Fix available
A fix is available. Upgrade to after 10.1.7 or later.
See remediation →
84/100
Remediation priority · High
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 fix for CVE-2023-24998 was incomplete for Apache Tomcat 11.0.0-M2 to 11.0.0-M4, 10.1.5 to 10.1.7, 9.0.71 to 9.0.73 and 8.5.85 to 8.5.87. If non-default HTTP connector settings were used such that the maxParameterCount could be reached using query string parameters and a request was submitted that supplied exactly maxParameterCount parameters in the query string, the limit for uploaded request parts could be bypassed with the potential for a denial of service to occur.

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

An incomplete fix for CVE-2023-24998 in Apache Tomcat allows bypassing limits on uploaded request parts when HTTP connector is configured with maxParameterCount that can be reached via query string parameters, potentially enabling denial of service.

MitigationUpgrade Apache Tomcat to versions 11.0.0-M5, 10.1.8, 9.0.74, or 8.5.88 or later to obtain the complete fix.

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:>= 8.5.85, <= 8.5.87>= 9.0.71, <= 9.0.73>= 10.1.5, <= 10.1.7= 11.0.0
Debian LinuxOperating system
Affected:= 12.0
7 Mode Transition ToolApplication
Affected:all versions

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:3.1/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 checks

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

  1. Identify Apache Tomcat installation and version
    Locate the Tomcat installation directory (commonly /opt/tomcat, /usr/share/tomcat, or a custom path). Check the version by examining the contents of the RELEASE-NOTE file in the Tomcat home directory, or by running 'sh catalina.sh version' if available.
    Affected if The installed version falls within these ranges: 8.5.85 to 8.5.87, 9.0.71 to 9.0.73, 10.1.5 to 10.1.7, or exactly 11.0.0.
  2. Locate server.xml connector configuration
    In the Tomcat installation, navigate to the conf directory and open server.xml. Identify the HTTP connector element (typically with protocol="HTTP/1.1").
    Affected if An HTTP connector is defined in server.xml.
  3. Check maxParameterCount connector attribute
    In the server.xml connector element, look for the maxParameterCount attribute. If not present, the default value of 10000 applies.
    Affected if The maxParameterCount attribute is configured on the HTTP connector.
  4. Assess query string exposure
    Review whether the Tomcat connector is exposed to the public internet or accepts HTTP requests containing query string parameters.
    Affected if The connector accepts external HTTP requests with query string parameters and has a configured maxParameterCount.

You are affected if you run Apache Tomcat version 8.5.85 through 8.5.87, 9.0.71 through 9.0.73, 10.1.5 through 10.1.7, or exactly 11.0.0, and have an HTTP connector configured with maxParameterCount that can be reached via query string parameters.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 10.1.7
Interim mitigation

Upgrade Apache Tomcat to versions 11.0.0-M5, 10.1.8, 9.0.74, or 8.5.88 or later to obtain the complete fix.

Recommended fix High confidence

Tomcat 8.5.88+ / 9.0.74+ / 10.1.8+ / 11.0.0-M5+ (depending on your major version)

  1. 1. Identify the current Apache Tomcat version by checking the release notes or the CATALINA_HOME/release-info.properties file
  2. 2. For Tomcat 8.5.x: Upgrade to version 8.5.88 or later
  3. 3. For Tomcat 9.0.x: Upgrade to version 9.0.74 or later
  4. 4. For Tomcat 10.1.x: Upgrade to version 10.1.8 or later
  5. 5. For Tomcat 11.0.x: Upgrade to version 11.0.0-M5 or later
  6. 6. Download the appropriate fixed version from https://tomcat.apache.org/
  7. 7. Stop the Tomcat service
  8. 8. Back up the current Tomcat installation including configuration files and web applications
Caveat Minor version upgrades typically have no breaking changes; however, always test in a non-production environment first, especially if using custom connector configurations with maxParameterCount settings

Generated from the published advisory — verify against the referenced sources before acting.

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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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-2023-28709 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