Messaging GatewayApplication · Symantec

CVE-2018-12243

HIGH · 8.8 CVSS v3.0 Published 2018-09-19
Fix available
A fix is available. Upgrade to 10.6.6 or later.
See remediation →
93/100
Remediation priority · Urgent
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 Symantec Messaging Gateway product prior to 10.6.6 may be susceptible to a XML external entity (XXE) exploit, which is a type of issue where XML input containing a reference to an external entity is processed by a weakly configured XML parser. The attack uses file URI schemes or relative paths in the system identifier to access files that should not normally be accessible.

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

This is an XML External Entity (XXE) injection vulnerability in Symantec Messaging Gateway versions prior to 10.6.6. The product's XML parser is weakly configured and processes external entity references, allowing authenticated attackers to access local files on the system using file URI schemes or relative paths.

MitigationApply the vendor patch to upgrade to Symantec Messaging Gateway version 10.6.6 or later, which contains the corrected XML parser configuration.

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
Messaging GatewayApplication
Affected:< 10.6.6

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:A/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. Confirm Symantec Messaging Gateway is installed
    Locate the SMG installation directory or check for the product via system inventory tools. Common paths include /opt/Symantec/SMG or C:\Program Files\Symantec\MessagingGateway on Windows.
    Affected if The product is not found on the system.
  2. Determine installed SMG version
    Access the SMG administration console and navigate to Help > About, or run the command line utility if available (such as 'smg --version' or check version info in the installation directory).
    Affected if The installed version is lower than 10.6.6 (for example, 10.6.5, 10.6.4, etc.).
  3. Verify XML import or parsing features are accessible
    Check if the SMG administration interface includes features that accept XML input, such as configuration import, policy import, or report templates that process XML documents.
    Affected if XML import or parsing features are enabled and accessible to authenticated users.
  4. Confirm remote authentication is enabled
    Review the SMG authentication settings in the administration console under Users > Authentication. Determine if LDAP, RADIUS, or local user accounts can authenticate remotely.
    Affected if Remote authentication is enabled and allows user logins.

The environment is affected if Symantec Messaging Gateway is installed with a version lower than 10.6.6 and XML parsing features are accessible to authenticated 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.

From vendor data
Upgrade available Upgrade to 10.6.6 or later
Fixed in 10.6.6
Interim mitigation

Apply the vendor patch to upgrade to Symantec Messaging Gateway version 10.6.6 or later, which contains the corrected XML parser configuration.

Fix this in Messaging Gateway 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

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-12243 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-12243 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