CVE-2023-33564
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 · uneditedThere is a Cross Site Scripting (XSS) vulnerability in the "theme" parameter of preview.php in PHPJabbers Time Slots Booking Calendar v3.3.
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 confidenceA reflected Cross Site Scripting (XSS) vulnerability exists in the 'theme' parameter of preview.php in PHPJabbers Time Slots Booking Calendar v3.3. An unauthenticated attacker can inject malicious JavaScript through the theme parameter which executes in the victim's browser when the crafted URL is visited.
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= 3.3CVSS 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
- 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 PHPJabbers Time Slots Booking Calendar installationSearch the web server document root for the booking calendar files, specifically looking for preview.phpAffected if The application is installed and preview.php is accessible via web
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Identify the installed versionCheck the application version by reviewing version files, headers, or the admin interface; look for version identifier '3.3'Affected if Version is exactly 3.3
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Confirm preview.php handles the theme parameterAccess the URL pattern: /preview.php?theme=test and inspect whether the theme parameter value appears in the HTTP response bodyAffected if The theme parameter value is reflected in the page output without sanitization
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Verify lack of output encoding on theme parameterRequest preview.php?theme=<script>alert(1)</script> and examine the raw HTML response to see if the script tags are rendered as plain text or executedAffected if The parameter value is inserted into HTML without encoding (visible <script> tags in response indicates vulnerability)
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Check if application is reachable without authenticationAttempt to access preview.php directly from the public URL without logging inAffected if The vulnerable endpoint is accessible to unauthenticated users
You are affected if PHPJabbers Time Slots Booking Calendar v3.3 is installed, preview.php is accessible, and the theme parameter is reflected in the HTTP response without HTML 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 strict input validation using a whitelist approach for the theme parameter, and apply proper output encoding before rendering the value in HTML responses.
- Consultation3.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2023-33564 — 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-2023-33564 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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