CVE-2021-26617
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 · uneditedThis issues due to insufficient verification of the various input values from user’s input. The vulnerability allows remote attackers to execute malicious code in Firstmall via navercheckout_add function.
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 confidenceA remote code execution vulnerability in Firstmall's navercheckout_add function allows attackers to inject malicious code due to insufficient validation of user input. The lack of proper input sanitization enables unauthenticated remote attackers to execute arbitrary code on the server.
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 dataall versionsCVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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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Confirm Firstmall installation existsSearch for Firstmall directories or files on the server, typically under web root paths like /var/www/html/, /home/*/public_html/, or check for files containing 'firstmall' or 'Firstmall' in name.Affected if Firstmall software is present on the server
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Locate the navercheckout_add functionSearch for the navercheckout_add function in the codebase - it is typically found in controller or model files related to naver checkout integration. Use grep to search for 'navercheckout_add' within the Firstmall directory.Affected if The navercheckout_add function file exists in the installation
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Verify function is web-accessibleCheck if the navercheckout_add function can be reached via HTTP/HTTPS requests - typically through a controller endpoint. Examine the routing configuration or directly attempt a request to the suspected endpoint (e.g., /navercheckout/add or similar URL patterns).Affected if The function is accessible via web requests without authentication
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Check for signs of exploitation or webshellsReview access logs for suspicious POST/GET requests to the navercheckout_add endpoint. Look for unusual files or scripts in the Firstmall directory, especially in writable folders. Search for recently created PHP files with suspicious code patterns.Affected if Unexpected requests to the function appear in logs, or unknown PHP scripts exist in the Firstmall directory
If Firstmall is installed and the navercheckout_add function is web-accessible, the environment is vulnerable since all versions are affected.
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 rigorous input validation and sanitization on all user-supplied parameters in the navercheckout_add function. Validate data types, length, and format before processing, and use parameterized queries or appropriate escaping mechanisms for any database or system command operations.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26617 — 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-2021-26617 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
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