Web ServerApplication · Codesys

CVE-2017-6025

CRITICAL · 9.8 CVSS v3.0 Published 2017-05-19
Fix available
A fix is available. Upgrade to after 2.3 or later.
See remediation →
100/100
Remediation priority · Urgent
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
A Stack Buffer Overflow issue was discovered in 3S-Smart Software Solutions GmbH CODESYS Web Server. The following versions of CODESYS Web Server, part of the CODESYS WebVisu web browser visualization software, are affected: CODESYS Web Server Versions 2.3 and prior. A malicious user could overflow the stack buffer by providing overly long strings to functions that handle the XML. Because the function does not verify string size before copying to memory, the attacker may then be able to crash the application or run arbitrary code.

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

A stack buffer overflow vulnerability exists in the CODESYS Web Server (versions 2.3 and prior) due to insufficient bounds checking in XML handling functions. When processing XML data, the application copies user-supplied strings to a fixed-size stack buffer without validating the string length, allowing an attacker to overwrite adjacent stack memory and potentially execute arbitrary code.

MitigationUpgrade to a patched version of CODESYS Web Server if available; otherwise, restrict network access to the web server and implement input validation at network perimeter devices.

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
Web ServerApplication
Affected:<= 2.3

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
High
Availability
High

CVSS:3.0/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 checks

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

  1. Identify if CODESYS Web Server is installed
    Look for CODESYS Web Server process or service on the system. Common installation paths may include C:\CODESYS\ or /opt/codesys/. Check running services or installed programs list.
    Affected if CODESYS Web Server version 2.3 or lower is installed and running
  2. Determine the installed CODESYS Web Server version
    Check the version information of the CODESYS Web Server executable or check version in the product documentation/installation files. Look for webserver.exe or similar binary and inspect its version properties.
    Affected if Version is 2.3 or any version prior to 2.3
  3. Verify web server is accessible and XML handling is enabled
    Confirm the web server is running and accepting connections. The vulnerability is in XML parsing functionality, so check if web-based XML interfaces or APIs are exposed.
    Affected if Web server is running and accessible on network with XML processing enabled
  4. Check for exposed XML endpoints or services
    Review web server configuration files or examine HTTP endpoints that handle XML data. Look for web interfaces that process XML input.
    Affected if XML-handling web endpoints are accessible to network users

You are affected if CODESYS Web Server version 2.3 or lower is installed, running, and has its web/XML interfaces accessible on the network.

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
Upgrade available Upgrade to a release after 2.3
Interim mitigation

Upgrade to a patched version of CODESYS Web Server if available; otherwise, restrict network access to the web server and implement input validation at network perimeter devices.

Fix this in Web Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA6.0 h
26.0 hours of engineering $4,520
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2017-6025 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-6025 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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