CVE-2025-24894
CVE-2025-24894
Weakness (CWE)
CVSS Vector
v3.1- Attack Vector
- Network
- Attack Complexity
- Low
- Privileges Required
- None
- User Interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Description
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.
Comprehensive Technical Analysis of CVE-2025-24894
1. Vulnerability Assessment and Severity Evaluation
CVE ID: CVE-2025-24894 CVSS Score: 9.1
The vulnerability in SPID.AspNetCore.Authentication, an AspNetCore Remote Authenticator for SPID, involves a flaw in the validation logic of SAML2 signatures. This flaw allows an attacker to inject a signed XML element as the first element, bypassing subsequent signature verifications. This can lead to the creation of arbitrary SAML responses, enabling user impersonation.
Severity Evaluation:
- CVSS Score: 9.1 (Critical)
- Impact: High
- Exploitability: High
The high CVSS score indicates a critical vulnerability that can be easily exploited with severe consequences, including unauthorized access and user impersonation.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- SAML Response Injection: An attacker can inject a legitimately signed XML element as the first element in a SAML response.
- User Impersonation: By crafting an arbitrary SAML response, an attacker can impersonate any SPID and/or CIE user.
Exploitation Methods:
- Metadata Exploitation: The attacker can use the IdP's public metadata to obtain a legitimately signed XML element.
- Signature Bypass: The attacker injects this signed element as the first element in a SAML response, bypassing subsequent signature verifications.
3. Affected Systems and Software Versions
Affected Systems:
- Systems using SPID.AspNetCore.Authentication for SAML2-based authentication.
Affected Software Versions:
- All versions prior to 3.4.0.
4. Recommended Mitigation Strategies
Immediate Actions:
- Upgrade: Upgrade to version 3.4.0 or later, which addresses the vulnerability.
- Monitoring: Implement monitoring for unusual authentication activities and SAML response patterns.
Long-Term Strategies:
- Code Review: Conduct a thorough code review of authentication mechanisms to identify and fix similar vulnerabilities.
- Security Training: Provide training for developers on secure coding practices, especially for SAML2 implementations.
- Regular Updates: Ensure regular updates and patches for all authentication libraries and frameworks.
5. Impact on Cybersecurity Landscape
Broader Implications:
- Trust Erosion: This vulnerability undermines the trust in SAML2-based authentication systems, which are widely used for single sign-on (SSO) implementations.
- Increased Risk: Organizations relying on SPID for authentication face increased risk of unauthorized access and data breaches.
- Compliance Issues: Non-compliance with security standards can lead to legal and regulatory consequences.
Industry-Wide Concerns:
- Supply Chain Risks: Vulnerabilities in widely-used authentication libraries can propagate risks across multiple organizations and sectors.
- Reputation Damage: Organizations experiencing breaches due to this vulnerability may suffer significant reputation damage.
6. Technical Details for Security Professionals
Vulnerability Details:
- Root Cause: The validation logic for SAML2 signatures does not ensure that the first signature refers to the root object, allowing signature bypass.
- Exploitation Steps:
- Obtain a legitimately signed XML element from the IdP's public metadata.
- Inject this element as the first element in a crafted SAML response.
- Submit the crafted SAML response to the Service Provider (SP), bypassing subsequent signature verifications.
Detection and Response:
- Log Analysis: Analyze authentication logs for unusual SAML response patterns and failed signature verifications.
- Intrusion Detection: Implement intrusion detection systems (IDS) to monitor for SAML response injection attempts.
- Incident Response: Develop an incident response plan specifically for SAML-based authentication vulnerabilities.
Conclusion: CVE-2025-24894 represents a critical vulnerability in SPID.AspNetCore.Authentication that can be exploited to impersonate users. Immediate mitigation through upgrading to the patched version is essential. Long-term strategies should focus on secure coding practices, regular updates, and robust monitoring to prevent similar vulnerabilities in the future. The broader impact on the cybersecurity landscape underscores the need for vigilant security practices and continuous improvement in authentication mechanisms.