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Improper AuthenticationWeakness · CWE-287

CVE-2025-24894

CRITICAL · 9.1 CVSS v3.1 Published 2025-02-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
SPID.AspNetCore.Authentication is an AspNetCore Remote Authenticator for SPID. Authentication using Spid and CIE is based on the SAML2 standard which provides two entities: Identity Provider (IDP): the system that authenticates users and provides identity information (SAML affirmation) to the Service Provider, in essence, is responsible for the management of the credentials and identity of users; Service Provider (SP): the system that provides a service to the user and relies on the Identity Provider to authenticate the user, receives SAML assertions from the IdP to grant access to resources. The validation logic of the signature is central as it ensures that you cannot create a SAML response with arbitrary assertions and then impersonate other users. There is no guarantee that the first signature refers to the root object, it follows that if an attacker injects an item signed as the first element, all other signatures will not be verified. The only requirement is to have an XML element legitimately signed by the IdP, a condition that is easily met using the IdP's public metadata. An attacker could create an arbitrary SAML response that would be accepted by SPs using vulnerable SDKs, allowing him to impersonate any Spid and/or CIE user. This vulnerability has been addressed in version 3.4.0 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

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

The SPID.AspNetCore.Authentication library has a signature validation flaw where the first signed XML element is not guaranteed to be the root object. An attacker can inject a legitimately signed IdP element as the first item, causing subsequent signatures to go unverified, enabling complete user impersonation without any prior authentication.

MitigationUpgrade to version 3.4.0 of SPID.AspNetCore.Authentication. No workarounds exist; immediate patching is required due to the critical severity and complete compromise potential.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Identify SPID.AspNetCore.Authentication package
    Search project files (.csproj, packages.config, .vbproj) or NuGet package manager for the package 'SPID.AspNetCore.Authentication' and note its installed version
    Affected if The package is present in the project with a version lower than 3.4.0
  2. Check for SAML2 authentication configuration
    Review the application's startup or program configuration files for calls to AddSpidAuthentication or AddCieAuthentication, and inspect the SAML-related configuration sections
    Affected if SAML2 authentication (SPID or CIE) is configured and active in the application
  3. Verify authentication flow uses SAML2 responses
    Examine the authentication handler configuration in appsettings.json, appsettings.Development.json, or custom configuration files for SAML2-specific settings such as EntityId, AssertionConsumerServiceUrl, or IdP metadata references
    Affected if The application processes SAML2 authentication responses from an external Identity Provider

The environment is affected if SPID.AspNetCore.Authentication version is below 3.4.0 and the application has SAML2 authentication enabled for SPID or CIE flows.

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

Upgrade to version 3.4.0 of SPID.AspNetCore.Authentication. No workarounds exist; immediate patching is required due to the critical severity and complete compromise potential.

Recommended fix High confidence

Version 3.4.0

  1. Identify the SPID.AspNetCore.Authentication package reference in your project (typically in .csproj, packages.config, or Directory.Build.props)
  2. Update the package reference to version 3.4.0 using your package manager (e.g., dotnet add package SPID.AspNetCore.Authentication --version 3.4.0, or update via NuGet package manager)
  3. Rebuild and test your application to ensure the upgrade doesn't introduce issues
  4. Deploy the updated application

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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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-2025-24894 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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