GuacamoleApplication · Apache
CVE-2016-1566
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 · uneditedCross-site scripting (XSS) vulnerability in the file browser in Guacamole 0.9.8 and 0.9.9, when file transfer is enabled to a location shared by multiple users, allows remote authenticated users to inject arbitrary web script or HTML via a crafted filename. NOTE: this vulnerability was fixed in guacamole.war on 2016-01-13, but the version number was not changed.
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 confidenceStored XSS vulnerability in Guacamole's file browser component. When file transfer is enabled to a shared location accessible by multiple users, an authenticated attacker can upload files with crafted filenames containing malicious JavaScript or HTML that executes when other users browse the shared folder.
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
GuacamoleApplication
= 0.9.8= 0.9.9CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:L/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 the installed Guacamole versionLocate the guacamole.war file or check the application metadata (typically found in the WAR file's MANIFEST.MF or the web interface footer). Run: unzip -p guacamole.war META-INF/MANIFEST.MF or check the server logs on startup for the version banner.Affected if The version listed is exactly 0.9.8 or 0.9.9
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Verify if file transfer is enabledExamine the Guacamole configuration file (guacamole.properties) for the enable-file-transfer property. Look for lines containing 'enable-file-transfer' and check if it is set to 'true'.Affected if File transfer is enabled (enable-file-transfer=true) in the configuration
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Confirm if a shared folder location is configuredIn guacamole.properties, locate the parameter defining the shared storage path, typically configured via 'file-transfer' related settings or a 'guacd' filesystem mount configuration. Search for paths pointing to shared/network directories.Affected if A shared folder path is configured and accessible by multiple users
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Inspect shared folder contents for suspicious filenamesBrowse to or list the contents of the configured shared folder. Look for files with unusual names containing patterns like <script>, javascript:, onerror=, or other HTML/JS event handlers.Affected if Files exist in the shared folder with names containing raw HTML tags or JavaScript code
A user is affected if Guacamole version is 0.9.8 or 0.9.9 AND file transfer is enabled to a shared location accessible by multiple 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 the patched guacamole.war (released 2016-01-13) or update to a version beyond 0.9.9. As a compensating control, consider disabling file transfer to shared locations or implementing filename sanitization at the storage layer.
Fix this in Guacamole
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-1566 — 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-2016-1566 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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