CVE-2021-37211
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 · uneditedThe bulletin function of Flygo does not filter special characters while a new announcement is added. Remoter attackers can use the vulnerability with general user’s credential to inject JavaScript and execute stored XSS attacks.
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 confidenceFlygo's bulletin/announcement function lacks proper input sanitization, allowing attackers with basic user credentials to inject malicious JavaScript via unsanitized fields. This stored XSS executes whenever other users view the affected bulletins.
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< 1.91.1CVSS 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:3.1/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 installed Flygo versionLocate the version information in the application admin panel, about page, or version file. This is typically found under Settings > About or in the application metadata.Affected if The installed version is below 1.91.1
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Confirm bulletin module is activeAccess the bulletin/announcement feature in the Flygo interface. Navigate to the announcements section visible to users (often labeled as Bulletins, Announcements, or News).Affected if The bulletin/announcement module is accessible and functional in the current deployment
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Verify user access to bulletin creationLog in with a basic user account (non-admin) and confirm if the ability to create or submit bulletins/announcements exists. Check user role permissions for bulletin creation.Affected if Basic authenticated users can create or submit bulletins
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Inspect existing bulletins for suspicious contentView the list of published bulletins and examine the content fields (title, body, author) for unusual characters such as <, >, script tags, or encoded payloads. Use browser developer tools to inspect the HTML source of bulletins.Affected if Bulletin entries contain unencoded HTML tags, script elements, or event handler attributes like onload, onerror, or onclick
Your environment is affected if Flygo version is below 1.91.1 AND the bulletin module is enabled AND basic users can create bulletins, regardless of whether malicious content is currently present.
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 data1.91.1
Implement input validation to reject special characters used in XSS attacks, and apply output encoding when displaying bulletins to prevent script execution.
- Consultation2.0 h
- Implementation4.0 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 $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-37211 — 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-2021-37211 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