CVE-2018-0686
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 · uneditedDenbun by NEOJAPAN Inc. (Denbun POP version V3.3P R4.0 and earlier, Denbun IMAP version V3.3I R4.0 and earlier) allows remote authenticated attackers to upload and execute any executable files via unspecified vectors.
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 confidenceDenbun webmail by NEOJAPAN Inc. versions V3.3P R4.0 and earlier (POP) and V3.3I R4.0 and earlier (IMAP) contains an authenticated file upload vulnerability allowing remote attackers with valid credentials to upload and execute arbitrary executable files, achieving remote code execution on the server.
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<= 3.3i_r4.0<= 3.3p_r4.0CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify Denbun webmail installationLook for Denbun webmail files in the web server document root or application directory. Common indicators include folders named 'denbun', 'Debun', or 'NeoDebun' and webmail login pages referencing 'Denbun' or 'NEOJAPAN'.Affected if Denbun webmail software is present on the server.
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Determine installed Denbun versionCheck for version information in the webmail interface (typically visible in the login page footer, about page, or administration panel) or check for version files within the Denbun installation directory.Affected if The installed version is Neo Debun Imap version 3.3i_r4.0 or lower, or Neo Debun Pop version 3.3p_r4.0 or lower.
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Confirm IMAP or POP service is enabledCheck the Denbun configuration files or administration panel to verify whether IMAP (Neo Debun Imap) or POP (Neo Debun Pop) connector services are enabled and in use.Affected if Either IMAP or POP connector is enabled and the version falls within the affected range.
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Verify remote authentication is accessibleConfirm that the webmail interface is accessible remotely over HTTP/HTTPS and allows user authentication. Check network exposure settings and authentication mechanisms.Affected if Remote authentication is enabled, allowing external users to obtain valid credentials.
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Inspect file upload functionalityLog into the webmail with valid credentials and attempt to locate the file attachment or file upload feature. Check if arbitrary file extensions can be attached to messages.Affected if The file upload feature accepts executable file types (such as .php, .asp, .exe, .cgi, .jsp) without restrictive validation.
A system is affected if it runs Denbun webmail (Neo Debun Imap <= 3.3i_r4.0 or Neo Debun Pop <= 3.3p_r4.0) with remote authentication enabled and has the vulnerable file upload functionality accessible to authenticated users.
Generated from the published advisory. Verify against your own configuration.
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 dataApply vendor-supplied patches when available; if no patch exists, implement compensating controls including strict file type validation, storing uploads outside webroot, disabling script execution in upload directories, network access restrictions, and aggressive input sanitization.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-0686 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-0686 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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