CVE-2023-53921
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 · uneditedSitemagicCMS 4.4.3 contains a remote code execution vulnerability that allows attackers to upload malicious PHP files to the files/images directory. Attackers can upload a .phar file with system command execution payload to compromise the web application and execute arbitrary system commands.
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 confidenceSitemagicCMS 4.4.3 suffers from an insecure file upload vulnerability allowing unauthenticated attackers to upload malicious .phar files containing PHP code with system() calls to the files/images directory. Since .phar files are executable by PHP, attackers can directly execute arbitrary system commands on the server, achieving full remote 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= 4.4.3CVSS 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 Sitemagic CMS versionLocate the version file or footer in the CMS installation. Common locations include a version.php file, README file, or the admin dashboard. Check the main index.php or configuration files for version strings.Affected if The installed version is exactly 4.4.3
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Verify files/images directory existsCheck the web root for the 'files/images' directory. This is the directory where uploads are accepted according to the CVE.Affected if The directory exists and is publicly accessible via the web server
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List .phar files in upload directoryUse a file manager or command line to list all files with .phar extension in the files/images directory. Run: ls -la /path/to/webroot/files/images/*.phar or dir /path\to\webroot\files\images\*.pharAffected if Any .phar files exist in the files/images directory
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Inspect suspicious PHP-related filesExamine any recently created or modified PHP, phar, or phtml files in the upload directory. Check file contents for system(), exec(), passthru(), or shell_exec() calls.Affected if Files containing PHP code with system execution functions exist in the upload directory
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Review web server access logsExamine web server access logs (Apache access.log, Nginx access.log) for POST requests to upload endpoints targeting the files/images directory. Look for .phar file uploads.Affected if Logs show unauthenticated POST requests uploading .phar files to the files/images directory
A system is affected if it runs Sitemagic CMS version 4.4.3 and has publicly accessible .phar files or evidence of unauthorized uploads in the files/images directory.
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 file upload validation (whitelist allowed extensions/MIME types, reject .phar and other executable extensions), store uploads outside webroot or disable PHP execution in upload directories, and remove any existing malicious files from the affected directory.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-53921 — 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-2023-53921 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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