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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
ColdfusionApplication · Adobe

CVE-2018-4939

CRITICAL · 9.8 CVSS v3.1 Published 2018-05-19
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
In the wild 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
Adobe ColdFusion Update 5 and earlier versions, ColdFusion 11 Update 13 and earlier versions have an exploitable Deserialization of Untrusted Data vulnerability. Successful exploitation could lead to arbitrary code execution.

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

Adobe ColdFusion versions prior to Update 6 (2018) and Update 14 (11) contain a deserialization vulnerability where untrusted data is insecurely processed during object reconstruction. Attackers can craft malicious serialized payloads that execute arbitrary code on the server upon deserialization.

MitigationApply Adobe ColdFusion security updates (Update 6 for ColdFusion 2018, Update 14 for ColdFusion 11) or upgrade to the latest supported version to remediate the insecure deserialization.

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
ColdfusionApplication
Affected:= 11.0= 2016

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 ColdFusion installed version
    Check the version file located in the ColdFusion installation directory, typically at {cf_root}/lib/coldfusion-version.properties, or log into the ColdFusion Administrator and view the Server Settings > ColdFusion Administrator page
    Affected if The installed version is ColdFusion 2018 Update 5 or earlier, or ColdFusion 11 Update 13 or earlier
  2. Confirm the specific update level
    In the ColdFusion Administrator, navigate to the System Information or Settings page to see the exact Update number installed
    Affected if The displayed Update number is 5 or lower for ColdFusion 2018, or 13 or lower for ColdFusion 11
  3. Verify BlazeDS or AMF endpoint exposure
    Check if the Flex/AMF endpoints are accessible by attempting to access URLs such as /flex2gateway/, /messagebroker/, or /cfamf/gateway from the server itself or externally
    Affected if These endpoints are reachable and the server is processing AMF (Action Message Format) deserialization without authentication restrictions
  4. Review deserialization configuration files
    Examine the WEB-INF/web.xml and WEB-INF/flex/services-config.xml files in the ColdFusion web root for enabled data services or message broker servlet mappings
    Affected if The messageBroker servlet or Flexservices are mapped and enabled without strict access controls
  5. Test for unauthenticated deserialization access
    Send a crafted AMF request to exposed endpoints using a tool like amfphp or a custom serialized payload to observe if the server attempts to deserialize untrusted data
    Affected if The server accepts and processes AMF or other serialized input without requiring authentication

The environment is affected if the installed ColdFusion version falls within the 2018 Update 5 or earlier range, or the 11 Update 13 or earlier range, and the server exposes deserialization endpoints to unauthenticated users.

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

Apply Adobe ColdFusion security updates (Update 6 for ColdFusion 2018, Update 14 for ColdFusion 11) or upgrade to the latest supported version to remediate the insecure deserialization.

Recommended fix High confidence

ColdFusion 11 Update 14+ or ColdFusion 2016 Update 6+; consider migrating to ColdFusion 2021 or 2023 for longer support

  1. Upgrade ColdFusion 11 to Update 14 or later by downloading from the Adobe ColdFusion downloads page
  2. Upgrade ColdFusion 2016 to Update 6 or later by downloading from the Adobe ColdFusion downloads page
  3. After upgrading, verify the installation by checking the ColdFusion Administrator > System Information page
  4. Review and restart ColdFusion services to ensure the update is fully applied
  5. Validate that the deserialization vulnerability is patched by confirming the ColdFusion version and update level
Caveat Review Adobe's update notes for any configuration or compatibility changes between updates; test applications in a staging environment before production deployment

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

Fix this in Coldfusion Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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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-2018-4939 in production — separate from our analysis above.

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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