CVE-2025-66631: Csla Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-wq34-7f4g-953v
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CWE-502
Published
Advisory Summary

CVE-2025-66631 is a HIGH remote code execution vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Csla libraries in the NuGet ecosystem. The issue involves csla affected by remote code execution via wcfproxy (netdatacontractserializer). Remediation is available by upgrading affected packages to version 6.0.0.

CVE-2025-66631 at a Glance

CVE Identifier CVE-2025-66631
GHSA Identifier GHSA-wq34-7f4g-953v
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Csla
Package Ecosystem NuGet
Published Date
Last Updated

How to Fix CVE-2025-66631

To remediate this vulnerability, upgrade all affected Csla dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Csla fixed: 6.0.0 
Upgrade Csla to 6.0.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for Csla

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-66631, inspect your project dependencies for Csla:

inspect dependencies for Csla

Analyze the terminal output to locate any version of Csla in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.0.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Csla, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact Versions of CSLA .NET prior to version 6 allow the use of WcfProxy. WcfProxy uses the NetDataContractSerializer (NDCS) which has known vulnerabilities that can allow remote execution of code during deserialization. NDCS itself is considered obsolete, and you should avoid using WcfProxy or upgrade to CSLA 6 or higher where this issue does not exist. ### Patches CSLA .NET version 6 and higher do not use WCF or NetDataContractSerializer. ### Workarounds If you are using a version CSLA .NET older than version 6, you should stop using WcfProxy in your data portal configuration. Doing this avoids the use of WCF and the NetDataContractSerializer, avoiding the vulnerability.

CVE-2025-66631 Affected Csla Versions

1 component(s)
Fixed Versions:
6.0.0
Product / Package Ecosystem Affected Versions Fixed Version
Csla
nuget/Csla
NuGet
< 6.0.0
6.0.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/MarimerLLC/csla/security/advisories/GHSA-wq34-7f4g-953v
NVD — CVE-2025-66631 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-66631
Csla Source Repository REPOSITORY
https://github.com/MarimerLLC/csla/issues/4001
Csla Source Repository REPOSITORY
https://github.com/MarimerLLC/csla/pull/4018
Csla Source Repository REPOSITORY
https://github.com/MarimerLLC/csla
learn.microsoft.com/en-us/dotnet/fundam... WEB
https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca2310

Frequently Asked Questions

What is CVE-2025-66631?
CVE-2025-66631 is a security vulnerability in Csla involving Csla affected by Remote Code Execution via WcfProxy (NetDataContractSerializer) under CWE-502: Deserialization of Untrusted Data.
Which Csla versions are affected?
Affected versions include releases prior to 6.0.0 across affected packages: Csla.
What version fixes CVE-2025-66631?
Upgrading to 6.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Csla affected?
Yes, Csla is affected in releases prior to 6.0.0. Upgrade your dependency to 6.0.0 or later.
What CWE is associated with CVE-2025-66631?
CVE-2025-66631 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check NuGet dependencies for CVE-2025-66631?
Run the dependency tree command: 'inspect dependencies for Csla'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wq34-7f4g-953v",
  "modified" : "2025-12-09T19:17:25Z",
  "published" : "2025-12-08T22:15:56Z",
  "aliases" : [ "CVE-2025-66631" ],
  "summary" : "Csla affected by Remote Code Execution via WcfProxy (NetDataContractSerializer)",
  "details" : "### Impact\nVersions of CSLA .NET prior to version 6 allow the use of WcfProxy. WcfProxy uses the NetDataContractSerializer (NDCS) which has known vulnerabilities that can allow remote execution of code during deserialization. NDCS itself is considered obsolete, and you should avoid using WcfProxy or upgrade to CSLA 6 or higher where this issue does not exist.\n\n### Patches\nCSLA .NET version 6 and higher do not use WCF or NetDataContractSerializer.\n\n### Workarounds\nIf you are using a version CSLA .NET older than version 6, you should stop using WcfProxy in your data portal configuration. Doing this avoids the use of WCF and the NetDataContractSerializer, avoiding the vulnerability.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Csla"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/MarimerLLC/csla/security/advisories/GHSA-wq34-7f4g-953v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-66631"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MarimerLLC/csla/issues/4001"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MarimerLLC/csla/pull/4018"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/MarimerLLC/csla"
  }, {
    "type" : "WEB",
    "url" : "https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca2310"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-12-08T22:15:56Z",
    "nvd_published_at" : "2025-12-09T16:18:22Z"
  }
}