CVE-2021-28109
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 · uneditedTranzWare (POI) FIMI before 4.2.20.4.2 allows login_tw.php reflected Cross-Site Scripting (XSS).
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 confidenceTranzWare (POI) FIMI before version 4.2.20.4.2 contains a reflected Cross-Site Scripting (XSS) vulnerability in the login_tw.php file. The vulnerability allows attackers to inject malicious JavaScript code through unsanitized user input that is reflected back in the server's response, potentially leading to session hijacking or credential theft.
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< 4.2.20.4.2CVSS 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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Locate TranzWare FIMI installation directorySearch the system for the TranzWare FIMI installation folder, typically found in web server document roots or application directories. Check common paths such as /var/www/, /opt/, or the web server's htdocs folder.Affected if The installation directory cannot be found or TranzWare FIMI is not installed on this system.
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Identify installed FIMI versionLocate the version file or about page within the TranzWare FIMI installation. Common version files may be named version.txt, about.php, or located in a config/include directory. Open the file and record the version number.Affected if The version is lower than 4.2.20.4.2 (e.g., 4.2.20.4.1, 4.2.19.x, or earlier).
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Verify presence of login_tw.phpNavigate to the web-accessible directory within the FIMI installation and confirm the existence of the login_tw.php file. This file is typically located in the application's root or public web folder.Affected if The login_tw.php file exists and is accessible via the web server.
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Confirm user input reflection in login_tw.phpSubmit a test request to login_tw.php with a harmless test string (such as a unique alphanumeric token) in the login parameters. Examine the HTTP response to verify whether the submitted string is reflected back unchanged in the page output.Affected if The test string is reflected in the response without sanitization, encoding, or removal, indicating unsanitized input handling.
A system is affected if it runs TranzWare FIMI version lower than 4.2.20.4.2 and the login_tw.php file is present and reflects unsanitized user input in its response.
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 data4.2.20.4.2
Upgrade TranzWare FIMI to version 4.2.20.4.2 or later. As a temporary measure, implement input validation and output encoding on the login_tw.php file, and consider deploying a WAF rule to block XSS payloads in the interim.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-28109 — 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-2021-28109 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
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