CVE-2018-8921
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 File Sharing Notify Toast in Synology Drive before 1.0.2-10275 allows remote authenticated users to inject arbitrary web script or HTML via the malicious file name.
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 confidenceA stored XSS vulnerability exists in the File Sharing Notify Toast component of Synology Drive. Authenticated users can inject malicious JavaScript or HTML into file names, which gets executed when other users view the file sharing notification toast.
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< 1.0.2-10275CVSS 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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Verify Synology Drive Server is installedAccess Synology DSM admin interface, open Package Center, and look for Synology Drive Server in the installed packages listAffected if Synology Drive Server is not installed, this CVE does not apply
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Determine installed version of Synology Drive ServerIn Package Center, click on Synology Drive Server and view the version number displayed in the package details paneAffected if Version cannot be determined or is lower than 1.0.2-10275
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Compare version to affected rangeCompare the installed version number to 1.0.2-10275 using standard version comparison (e.g., 1.0.2-10270 < 1.0.2-10275)Affected if Installed version is less than 1.0.2-10275, indicating vulnerability to this CVE
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Check if File Sharing functionality is accessibleVerify that users have access to the file sharing feature in Synology Drive (check user permissions and Drive sharing settings)Affected if File sharing is enabled and users can share files, creating the attack surface for the XSS
User is affected if Synology Drive Server is installed with a version lower than 1.0.2-10275 and the File Sharing feature is enabled for at least one user.
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 data1.0.2-10275
Update Synology Drive to version 1.0.2-10275 or later to patch the XSS vulnerability in the file name handling routine.
- Consultation1.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-8921 — 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-2018-8921 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