CVE-2021-39412
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 · uneditedMultiple Cross Site Scripting (XSS) vulnerabilities exists in PHPGurukul Shopping v3.1 via the (1) callback parameter in (a) server_side/scripts/id_jsonp.php, (b) server_side/scripts/jsonp.php, and (c) scripts/objects_jsonp.php, the (2) value parameter in examples_support/editable_ajax.php, and the (3) PHP_SELF parameter in captcha/index.php.
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 confidenceMultiple reflected Cross-Site Scripting (XSS) vulnerabilities exist in PHPGurukul Shopping v3.1 where user-supplied input is rendered without proper sanitization. The vulnerable parameters include the callback parameter in three JSONP endpoints (id_jsonp.php, jsonp.php, objects_jsonp.php), the value parameter in editable_ajax.php, and the PHP_SELF variable in captcha/index.php. An attacker could inject malicious JavaScript code that executes in the context of a victim's browser session.
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= 3.1CVSS 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
- 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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Verify Shopping Portal version is 3.1Check the application source code for a version identifier, typically in a config file, footer, or README file included with the installation.Affected if The installed version is exactly 3.1 or if version identification shows this specific release.
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Inspect JSONP endpoint callback parameter in id_jsonp.phpLocate id_jsonp.php in the web root and examine how the callback parameter is handled - look for any echo or print statements that output this parameter without sanitization.Affected if The callback parameter from the request is reflected directly in the response without htmlspecialchars or similar encoding.
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Inspect JSONP endpoint callback parameter in jsonp.phpLocate jsonp.php and examine the code that processes and outputs the callback parameter.Affected if The callback parameter is echoed back to the browser without proper encoding.
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Inspect JSONP endpoint callback parameter in objects_jsonp.phpLocate objects_jsonp.php and review the code handling the callback parameter output.Affected if The callback parameter is reflected in the response without sanitization.
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Inspect editable_ajax.php value parameterLocate editable_ajax.php and find where the value parameter is processed and output.Affected if The value parameter from user input is rendered in the response without htmlspecialchars encoding.
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Inspect captcha/index.php PHP_SELF usageLocate captcha/index.php and examine form action attributes that use PHP_SELF - check if the variable is escaped before being placed in the HTML.Affected if The PHP_SELF server variable is inserted into a form action or other HTML attribute without htmlspecialchars encoding.
A user is affected if they are running Shopping Portal version 3.1 and any of the five vulnerable parameters (callback in three JSONP files, value in editable_ajax.php, or PHP_SELF in captcha/index.php) are accessible and output user input without 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 input validation to restrict acceptable characters (e.g., alphanumeric only for callback) and apply output encoding (htmlspecialchars with ENT_QUOTES) before rendering any user-controlled input back to the browser. For PHP_SELF specifically, ensure the form action is properly escaped.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39412 — 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-2021-39412 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
- No spam, self-promotion, credentials, or personal data