CVE-2021-33021
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 · uneditedxArrow SCADA versions 7.2 and prior is vulnerable to cross-site scripting due to parameter ‘edate’ of the resource xhisalarm.htm, which may allow an unauthorized attacker to execute arbitrary code.
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 confidencexArrow SCADA versions 7.2 and prior contains a stored cross-site scripting (XSS) vulnerability in the 'edate' parameter of the xhisalarm.htm resource. An unauthenticated attacker can inject malicious JavaScript code that executes in the context of victim users' browsers, potentially leading to session hijacking or arbitrary code execution.
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<= 7.2CVSS 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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Identify if xArrow SCADA is installedCheck for xArrow SCADA installation directories, services, or running processes on the system. Common installation paths may include Program Files directories or SCADA-specific folders.Affected if xArrow SCADA software is present on the system
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Determine installed xArrow versionLocate version information in the installation directory, typically found in about dialogs, release notes, or version files within the xArrow installation folder. Compare the version number to the affected range <= 7.2.Affected if Installed version is 7.2 or any earlier version
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Verify xhisalarm.htm resource existsCheck the web server configuration or document root for the presence of the xhisalarm.htm file. This file is the vulnerable component that processes the 'edate' parameter.Affected if xhisalarm.htm file exists in the accessible web directory
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Inspect web server access logs for edate parameter usageReview web server logs (IIS, Apache, or embedded server logs) for requests to xhisalarm.htm that include the 'edate' parameter. Look for patterns indicating the parameter is being processed.Affected if The 'edate' parameter is being received and processed by the application without sanitization
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Test for XSS vulnerability in edate parameterIf you have authorization, send a benign test payload in the 'edate' parameter (such as <script>alert(1)</script>) to xhisalarm.htm and observe if the payload is reflected unescaped in the response.Affected if The injected script content appears verbatim in the page response without HTML encoding
A system is affected if xArrow SCADA version 7.2 or earlier is installed and the xhisalarm.htm web resource with the 'edate' parameter is accessible and reflects input without proper encoding.
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 dataImplement strict input validation and output encoding for the 'edate' parameter; apply vendor patch if available; consider implementing Content Security Policy headers to mitigate XSS risks.
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33021 — 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-2021-33021 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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