dbcve.org
Csla .netApplication · Cslanet

CVE-2025-66631

CRITICAL · 9.8 CVSS v3.1 Published 2025-12-09
Fix available
A fix is available. Upgrade to 6.0.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
CSLA .NET is a framework designed for the development of reusable, object-oriented business layers for applications. Versions 5.5.4 and below allow the use of WcfProxy. WcfProxy uses the now-obsolete NetDataContractSerializer (NDCS) and is vulnerable to remote code execution during deserialization. This vulnerability is fixed in version 6.0.0. To workaround this issue, remove the WcfProxy in data portal configurations.

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

CSLA .NET framework versions 5.5.4 and below include WcfProxy which utilizes the obsolete NetDataContractSerializer (NDCS). NDCS is vulnerable to insecure deserialization attacks allowing remote code execution when malicious data is deserialized by the proxy.

MitigationUpgrade to CSLA .NET version 6.0.0 or remove WcfProxy from data portal configurations as a workaround.

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
Csla .netApplication
Affected:< 6.0.0

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
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 checks

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

  1. Identify CSLA .NET version in your project
    Check the NuGet package reference version, assembly file version, or version in your .csproj / packages.config for Csla. Look for any version below 6.0.0
    Affected if The installed or referenced CSLA .NET version is 5.5.4 or below, or any version below 6.0.0
  2. Locate WcfProxy configuration in your data portal
    Search your application configuration files (app.config, web.config) and source code for WcfProxy, WcfDataPortal, or NetDataContractSerializer references. Also check where the data portal is configured in your application startup code
    Affected if WcfProxy is configured as the data portal channel or NetDataContractSerializer is being used
  3. Verify WcfProxy is actively in use at runtime
    Review your application startup code, initialization scripts, or configuration where the CSLA data portal channel is set. Look for calls that set the portal type to WcfPortal or similar WCF proxy configuration
    Affected if The application initializes or loads WcfProxy as the active data portal channel during runtime
  4. Check for NDCS in serialization configuration
    Search config files and code for NetDataContractSerializer or NDCS usage, or for WCF bindings that may use this serializer
    Affected if NetDataContractSerializer is explicitly configured or implied by WcfProxy usage

You are affected if you are using any CSLA .NET version below 6.0.0 AND WcfProxy is configured as your data portal channel, enabling NDCS-based deserialization of potentially malicious data.

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.

dbcve · scoped
Upgrade available Upgrade to 6.0.0 or later
Fixed in 6.0.0
Vendor patch github.com →
Interim mitigation

Upgrade to CSLA .NET version 6.0.0 or remove WcfProxy from data portal configurations as a workaround.

Recommended fix High confidence

CSLA .NET 6.0.0

  1. Upgrade CSLA .NET to version 6.0.0 or later to resolve the vulnerability
  2. If immediate upgrade is not possible, remove WcfProxy from the data portal configuration to eliminate the attack surface
  3. Review application configuration files (app.config or web.config) for any WcfPortal or WcfProxy implementations and remove or replace them with secure alternatives
Caveat Version 6.0.0 is a major version upgrade; review the CSLA .NET 6.0.0 release notes for breaking changes and API migrations

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Csla .net Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2025-66631 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