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OpensisApplication · Os4ed

CVE-2023-38879

HIGH · 7.5 CVSS v3.1 Published 2023-11-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
The Community Edition version 9.0 of OS4ED's openSIS Classic allows remote attackers to read arbitrary files via a directory traversal vulnerability in the 'filename' parameter of 'DownloadWindow.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 confidence

OS4ED openSIS Classic version 9.0 contains a directory traversal vulnerability in DownloadWindow.php via the 'filename' parameter, allowing unauthenticated remote attackers to read arbitrary files on the server by manipulating file paths with traversal sequences (e.g., ../../).

MitigationImplement strict input validation on the filename parameter to reject path traversal sequences, normalize file paths before access, and restrict downloads to an allowed directory whitelist.

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
OpensisApplication
Affected:= 9.0

CVSS 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
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm OS4ED openSIS Classic is installed
    Locate the openSIS installation directory, typically found in web server document roots (e.g., /var/www/html/opensis, C:\inetpub\wwwroot\opensis, or similar). Look for the presence of openSIS application files.
    Affected if The application is installed on the server in a web-accessible directory.
  2. Verify the version is 9.0
    Check the version information in the installation. Common locations include: a VERSION file in the root directory, the header section of the main index.php file, or the /includes/Config.php file. Compare your installed version to the affected range (9.0).
    Affected if The installed version is exactly 9.0.
  3. Confirm DownloadWindow.php exists
    Locate the file DownloadWindow.php within the installation directory. This file is typically found in the root directory or under /pages/ subdirectory of the openSIS installation.
    Affected if The file DownloadWindow.php exists in the openSIS installation directory.
  4. Check if the vulnerable filename parameter is accessible
    Access the DownloadWindow.php file via HTTP/HTTPS request (e.g., https://your-server/opensis/DownloadWindow.php). If the page loads without authentication or returns a response, the endpoint is web-accessible.
    Affected if The DownloadWindow.php file is accessible via web without requiring authentication.
  5. Inspect the filename parameter handling
    Examine the DownloadWindow.php source code, specifically looking for how the 'filename' parameter is processed. Search for uses of $_GET['filename'] or $_REQUEST['filename'] and check if path traversal sequences (../, ..\) are being validated or filtered before file operations.
    Affected if The code uses the filename parameter in file operations without proper validation or sanitization of path traversal sequences.

If OS4ED openSIS Classic version 9.0 is installed, the DownloadWindow.php file exists, and the filename parameter is accessible without authentication and lacks path traversal validation, the environment is affected by this CVE.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict input validation on the filename parameter to reject path traversal sequences, normalize file paths before access, and restrict downloads to an allowed directory whitelist.

Fix this in Opensis Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-38879 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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