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Jboss Enterprise Application PlatformApplication · Redhat

CVE-2016-3110

HIGH · 7.5 CVSS v3.0 Published 2016-09-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
mod_cluster, as used in Red Hat JBoss Web Server 2.1, allows remote attackers to cause a denial of service (Apache http server crash) via an MCMP message containing a series of = (equals) characters after a legitimate element.

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 confidence

A denial of service vulnerability in mod_cluster (JBoss Web Server 2.1) allows remote attackers to crash the Apache HTTP Server by sending malformed MCMP messages containing excessive '=' characters appended after legitimate message elements, causing the parser to fail.

MitigationApply the relevant patch or upgrade to a patched version of JBoss Web Server 2.1 that addresses this mod_cluster vulnerability; network-level filtering to restrict MCMP traffic to trusted sources may provide temporary protection.

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
Jboss Enterprise Application PlatformApplication
Affected:= 6.0.0= 6.4.0
Jboss Enterprise Web ServerApplication
Affected:= 2.0.0= 2.1
FedoraOperating system
Affected:= 28= 29= 30

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. Verify mod_cluster module is loaded in Apache
    Run 'httpd -M' or 'apachectl -M' to list loaded modules and search for 'mod_cluster' or 'cluster_module'
    Affected if mod_cluster module appears in the loaded modules list, indicating the vulnerable component is active
  2. Check JBoss Enterprise Web Server version
    Inspect the version file typically located at $JBOSS_HOME/bin/version.sh or check the installed RPM package with 'rpm -q jbossweb'
    Affected if Version is 2.0.0, 2.1, or matches 6.0.0/6.4.0 for JBoss Enterprise Application Platform, placing it within the affected range
  3. Confirm MCMP listener is configured and active
    Examine Apache configuration files (httpd.conf, mod_cluster.conf) for 'Listen' directives on the mod_cluster management port (default 6666) and check for 'EnableMCPMReceive' directive
    Affected if MCMP receive is explicitly enabled via 'EnableMCPMReceive' or the mod_cluster listener port is open and accepting traffic
  4. Review Apache error logs for parser failure signatures
    Search error logs (typically /var/log/httpd/error_log or /var/log/apache2/error.log) for entries containing 'mod_cluster' and 'parse' or '=' characters causing failures
    Affected if Recent error log entries show mod_cluster parsing failures related to malformed MCMP messages with excessive '=' characters
  5. Check Fedora system package version
    If running Fedora 28, 29, or 30, run 'rpm -qa | grep mod_cluster' to query the installed mod_cluster package version
    Affected if mod_cluster package version matches the vulnerable Fedora releases (28, 29, or 30)

You are affected if mod_cluster is loaded and the installed JBoss/Web Server version falls within 6.0.0, 6.4.0, 2.0.0, or 2.1 (or Fedora 28-30 with mod_cluster), AND MCMP traffic is being accepted on your mod_cluster listener port.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant patch or upgrade to a patched version of JBoss Web Server 2.1 that addresses this mod_cluster vulnerability; network-level filtering to restrict MCMP traffic to trusted sources may provide temporary protection.

Fix this in Jboss Enterprise Application Platform Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2016-3110 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
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  • Version or environment caveats, and links to real fixes
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