CVE-2017-5621
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 · uneditedAn issue was discovered in Zammad before 1.0.4, 1.1.x before 1.1.3, and 1.2.x before 1.2.1. XSS can be triggered via malicious HTML in a chat message or the content of a ticket article, when using either the REST API or the WebSocket API.
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 help desk software before versions 1.0.4, 1.1.3, and 1.2.1 contains a stored XSS vulnerability where malicious HTML/JavaScript can be injected through chat messages or ticket article content via the REST API or WebSocket API. The application fails to properly sanitize user input, allowing attackers to execute arbitrary scripts in the browsers of other users viewing the affected content.
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<= 1.0.3= 1.1.0= 1.1.1= 1.1.2= 1.2.0CVSS 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.
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Identify Zammad versionRun 'zammad --version' from the Zammad installation directory, or check the admin interface under Admin > System > Information to view the installed version numberAffected if The version displayed is 1.0.3 or lower, 1.1.0, 1.1.1, 1.1.2, or 1.2.0
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Verify API access is enabledCheck if the REST API or WebSocket API endpoints are accessible by attempting to reach https://your-zammad-host/api/v1/ or by reviewing the web server configuration for API route definitionsAffected if API endpoints are exposed and accessible without additional authentication restrictions beyond standard Zammad authentication
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Review API access logs for malicious inputExamine Zammad production logs (typically found in /var/log/zammad/ or the log directory of the Zammad installation) for API POST requests to /api/v1/ or WebSocket connections containing HTML tags, script elements, or JavaScript event handlers in ticket or chat content fieldsAffected if Log entries show API submissions containing unsanitized HTML/JavaScript payload patterns in ticket_article, chat_message, or similar content fields
You are affected if your Zammad version matches <= 1.0.3, 1.1.0-1.1.2, or 1.2.0 AND the REST API or WebSocket API is accessible to untrusted users who can submit ticket or chat content.
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 dataUpdate Zammad to version 1.0.4, 1.1.3, 1.2.1 or later to obtain the patch. Alternatively, implement server-side input validation and output encoding as a defense-in-depth measure.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2017-5621 — 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-2017-5621 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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- 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
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