Mdaemon Email ServerApplication · Altn

CVE-2019-13612

HIGH · 7.5 CVSS v3.0 Published 2019-07-16
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
MDaemon Email Server 19 through 20.0.1 skips SpamAssassin checks by default for e-mail messages larger than 2 MB (and limits checks to 10 MB even with special configuration), which is arguably inconsistent with currently popular message sizes. This might interfere with risk management for malicious e-mail, if a customer deploys a server with sufficient resources to scan large messages.

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

MDaemon Email Server versions 19 through 20.0.1 implement a hardcoded size threshold that bypasses SpamAssassin filtering for emails exceeding 2 MB by default (configurable up to 10 MB maximum). This design limitation allows large malicious emails to evade spam detection entirely, as the server skips the SpamAssassin analysis for messages above this threshold.

MitigationOrganizations should review their email traffic patterns to determine exposure, configure the maximum size limit if possible within the 10 MB constraint, consider upgrading to patched versions, and implement compensating controls such as additional gateway scanning or attachment sandboxing for large messages.

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
Mdaemon Email ServerApplication
Affected:= 19

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. Check MDaemon version installed
    Open the MDaemon GUI, go to Help > About, or check the registry key HKLM\SOFTWARE\Alt-N Technologies\MDaemon\Version
    Affected if Version is 19.x through 20.0.1 (check if version falls within 19.0.0 to 20.0.1 range)
  2. Verify SpamAssassin integration is enabled
    In MDaemon, navigate to Security > Spam Filter > Settings, or check the spam.ini configuration file in the MDaemon\app folder for SpamAssassinEnabled=1
    Affected if SpamAssassin is enabled (the bypass only matters if SpamAssassin is actually in use)
  3. Locate the Spam Filter size threshold setting
    In MDaemon GUI, go to Security > Spam Filter > Settings and look for the 'Skip SpamAssassin for messages larger than' option, or examine the spam.ini file for a MaxSize entry
    Affected if Threshold is set to a value of 2 MB or higher (default is 2 MB, up to 10 MB configurable - any non-zero value creates the bypass condition)
  4. Confirm the threshold is at default or elevated setting
    If the threshold setting is not visible in the GUI, review the spam.ini file in the MDaemon\app directory for the SpamAssassinMaxSize parameter
    Affected if SpamAssassinMaxSize is greater than 0 (any value enables the bypass for messages exceeding that size)
  5. Identify if email traffic includes messages over the threshold
    Review MDaemon logs (in MDaemon\Logs\ directory) or message tracking for messages larger than the configured threshold, or use the Queue Viewer to inspect message sizes
    Affected if The organization processes or has processed email attachments/messages exceeding the configured threshold (2 MB by default)
  6. Check if alternative spam filtering is configured
    Review Security > Spam Filter settings to see if third-party gateway filtering, content filters, or other anti-spam solutions are enabled alongside or instead of SpamAssassin
    Affected if No compensating spam controls exist for messages that bypass SpamAssassin due to size threshold

You are affected if running MDaemon 19.x-20.0.1 with SpamAssassin enabled and the size threshold is set to any value greater than 0, allowing large emails to bypass spam detection entirely.

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

Organizations should review their email traffic patterns to determine exposure, configure the maximum size limit if possible within the 10 MB constraint, consider upgrading to patched versions, and implement compensating controls such as additional gateway scanning or attachment sandboxing for large messages.

Fix this in Mdaemon Email Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,690
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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-2019-13612 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