Debun ImapApplication · Neo

CVE-2018-0684

CRITICAL · 9.8 CVSS v3.0 Published 2018-11-15
Fix available
A fix is available. Upgrade to after 3.3p_r4.0 or later.
See remediation →
100/100
Remediation priority · Urgent
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
Buffer overflow in Denbun by NEOJAPAN Inc. (Denbun POP version V3.3P R3.0 and earlier, Denbun IMAP version V3.3I R3.0 and earlier) allows remote attackers to execute arbitrary code or cause a denial-of-service (DoS) condition via multipart/form-data format data.

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

A buffer overflow vulnerability in Denbun webmail (both POP and IMAP versions up to V3.3P R3.0/V3.3I R3.0) allows remote attackers to send specially crafted multipart/form-data requests to overflow a buffer, potentially achieving remote code execution or causing denial of service.

MitigationApply the vendor-supplied patch or upgrade to a fixed version of Denbun. If immediate patching is not possible, restrict network access to the webmail interface using firewall rules or VPN access controls.

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
Debun ImapApplication
Affected:<= 3.3i_r4.0
Debun PopApplication
Affected:<= 3.3p_r4.0

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:3.0/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 Denbun installation and version
    Locate the Denbun installation directory and check for version files. Common locations include the web root (e.g., /var/www/html/denbun, C:\inetpub\wwwroot\denbun, or the application's root folder). Look for a version.txt, about page, or configuration file that displays the version number in format like 3.3i_rX.X or 3.3p_rX.X
    Affected if The installed version is 3.3i_r4.0 or lower for IMAP version, or 3.3p_r4.0 or lower for POP version
  2. Confirm product type (IMAP or POP)
    Determine whether the Denbun installation is the IMAP version (Neo Debun Imap) or POP version (Neo Debun Pop). Check the product name displayed in the webmail login page, about section, or installation documentation. The version string contains 'i' for IMAP (e.g., 3.3i_r3.0) or 'p' for POP (e.g., 3.3p_r3.0)
    Affected if The product is Neo Debun Imap version <= 3.3i_r4.0 or Neo Debun Pop version <= 3.3p_r4.0
  3. Verify web interface is accessible
    Confirm the Denbun webmail interface is reachable over HTTP/HTTPS. Test access to the login page URL (typically /denbun/login.cgi or similar). Check if the web server (IIS or Apache) hosting Denbun is running and accepting connections
    Affected if The Denbun web interface is exposed and accessible to network attackers, enabling them to send malicious multipart/form-data requests

You are affected if your Denbun webmail is version 3.3i_r4.0 or lower (IMAP) or 3.3p_r4.0 or lower (POP) and the web interface is network-accessible.

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 a release after 3.3p_r4.0
Interim mitigation

Apply the vendor-supplied patch or upgrade to a fixed version of Denbun. If immediate patching is not possible, restrict network access to the webmail interface using firewall rules or VPN access controls.

Fix this in Debun Imap Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-0684 — 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-2018-0684 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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