CVE-2018-1000154
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 · uneditedZammad GmbH Zammad version 2.3.0 and earlier contains a Improper Neutralization of Script-Related HTML Tags in a Web Page (CWE-80) vulnerability in the subject of emails which are not html quoted in certain cases. This can result in the embedding and execution of java script code on users browser. This attack appear to be exploitable via the victim openning a ticket. This vulnerability appears to have been fixed in 2.3.1, 2.2.2 and 2.1.3.
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 confidenceZammad versions 2.3.0 and earlier fail to properly sanitize HTML in email subject lines that are not HTML-quoted, allowing injection of script tags. When users view affected tickets in their browser, the embedded JavaScript executes, enabling session hijacking or other client-side attacks.
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<= 2.3.0CVSS 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
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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.
-
Check Zammad versionAccess the Zammad admin panel or run `zammad --version` in the installation directory to identify the installed version.Affected if The installed version is 2.3.0 or earlier.
-
Verify HTML rendering in email subjectsIn Zammad admin settings, navigate to System > Settings > Ticket > Email > HTML in Subject and verify whether HTML rendering for email subjects is enabled.Affected if HTML rendering in email subjects is turned on.
-
Inspect ticket subjects for HTML contentUse the Zammad search interface or database query to retrieve ticket subjects containing HTML tags such as <script>, <iframe>, or other HTML markup from the tickets table.Affected if Tickets exist with unescaped HTML or script tags in subject lines that originated from external emails.
-
Check ticket display behaviorOpen a ticket in the web browser that contains HTML in the subject line and inspect the page source to verify whether HTML is being rendered as code rather than displayed as text.Affected if The browser executes the HTML or JavaScript from email subjects instead of displaying it as plain text.
You are affected if your Zammad version is 2.3.0 or earlier AND HTML rendering for email subjects is enabled AND your system has processed external emails with malicious HTML in subject lines.
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 dataUpgrade Zammad to version 2.3.1, 2.2.2, or 2.1.3 or later. Until then, disable HTML rendering in email subjects or implement input validation at the mail gateway.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-1000154 — 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-2018-1000154 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
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.
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