CVE-2021-20750
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 vulnerability in EC-CUBE EC-CUBE 3.0.0 to 3.0.18-p2 (EC-CUBE 3 series) and EC-CUBE 4.0.0 to 4.0.5-p1 (EC-CUBE 4 series) allows a remote attacker to inject an arbitrary script by leading an administrator or a user to a specially crafted page and to perform a specific operation.
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 confidenceCross-site scripting (XSS) vulnerability in EC-CUBE e-commerce platform versions 3.0.0-3.0.18-p2 and 4.0.0-4.0.5-p1 allows remote attackers to inject arbitrary script through a specially crafted URL that tricks administrators or users into performing specific operations.
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>= 3.0.0, < 3.0.18>= 4.0.0, < 4.0.5= 3.0.18= 4.0.5CVSS 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:3.1/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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Locate EC-CUBE installation directoryIdentify the webroot directory where EC-CUBE is installed. Look for composer.json, index.php, or config files that confirm EC-CUBE presence.Affected if The installation directory exists and contains EC-CUBE files
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Find installed EC-CUBE versionOpen composer.json in the EC-CUBE root directory and locate the 'version' field under 'require' for ec-cube/ec-cube, or check src/Eccube/Application.php for a VERSION constant.Affected if The version field shows a version number that falls within the affected ranges
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Compare version against affected rangesCheck if the installed version is 3.0.0 through 3.0.18-p2 (or 3.0.18, 3.0.18-p1), or 4.0.0 through 4.0.5-p1 (or 4.0.5, 4.0.5-p1). Versions below 3.0.18-p3 or below 4.0.5-p2 are affected.Affected if Version is less than 3.0.18-p3 for series 3, or less than 4.0.5-p2 for series 4
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Verify admin panel accessibilityConfirm the EC-CUBE admin panel is accessible at /admin or similar path, since the XSS vulnerability targets administrators or users through specially crafted URLs.Affected if The admin panel is publicly or internally accessible
Your environment is affected if EC-CUBE version is 3.0.0 through 3.0.18-p2 or 4.0.0 through 4.0.5-p1, and the application is actively running.
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 data3.0.184.0.5
Upgrade to EC-CUBE versions 3.0.18-p3 or later for series 3, and 4.0.5-p2 or later for series 4, or apply vendor-supplied patches that implement proper input validation and output encoding.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20750 — 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-2021-20750 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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