CVE-2025-29774

Remediation/Mitigation Strategy: CVE-2025-29774 - XML Signature Bypass in xml-crypto

This document outlines a remediation and mitigation strategy for CVE-2025-29774, a critical vulnerability affecting the xml-crypto Node.js library.

1. Vulnerability Description:

  • Vulnerability: XML Signature Bypass
  • Affected Software: xml-crypto Node.js library
  • Affected Versions: Versions prior to 6.0.1, 3.2.1, and 2.1.6
  • Description: A vulnerability exists in the xml-crypto library that allows an attacker to modify a valid signed XML message in a way that bypasses signature verification checks. This means an attacker can alter the content of a signed XML document after it has been signed, without invalidating the signature.

2. Severity:

  • CVSS Score: 9.3 (Critical)
  • Severity Level: Critical
  • Impact: Successful exploitation of this vulnerability can lead to:
    • Authentication Bypass: An attacker could forge or manipulate authentication tokens.
    • Authorization Bypass: An attacker could gain unauthorized access to resources or functions.
    • Privilege Escalation: An attacker with limited privileges could escalate their privileges to those of a higher-level user or administrator.
    • Data Tampering: An attacker could modify sensitive data within signed XML documents.
    • Impersonation: An attacker could impersonate another user.

3. Known Exploits:

While the specifics of the exploit are not explicitly detailed in the provided information, the vulnerability allows for manipulating signed XML messages while maintaining a valid signature. A potential exploit scenario is described as altering critical identity or access control attributes. This suggests exploit techniques involve:

  • XML Rewriting: Modifying the XML structure or content in a way that doesn’t invalidate the signature. This might involve adding or modifying elements within the signed area or manipulating namespaces.
  • Signature Wrapping Attacks: Tricking the application into validating a different part of the XML document than intended, allowing malicious content to be processed.

4. Remediation Strategy:

The primary remediation strategy is to update the xml-crypto library to a patched version.

  • Upgrade xml-crypto: The most important step is to upgrade your application’s dependency on xml-crypto to one of the following patched versions:

    • Version 6.0.1 or later: If you are using xml-crypto version 6.0.0 or earlier, upgrade to version 6.0.1 or a newer release.
    • Version 3.2.1 or later: If you are using xml-crypto version 3.x, upgrade to version 3.2.1 or a newer release within the 3.x branch if available.
    • Version 2.1.6 or later: If you are using xml-crypto version 2.x, upgrade to version 2.1.6 or a newer release within the 2.x branch if available.

  • Verification: After upgrading, thoroughly test your application to ensure that the upgrade hasn’t introduced any regressions and that signature verification is working as expected. Include tests specifically designed to simulate potential exploitation attempts.

5. Mitigation Strategy (If Immediate Upgrade is Not Possible):

If an immediate upgrade is not possible, the following mitigation measures should be considered:

  • Input Validation: Implement strict input validation on all XML documents before processing them. Validate the structure, schema, and data types of the XML. Reject any documents that deviate from the expected format.
  • Signature Verification Hardening: Review and potentially strengthen your signature verification logic.
    • Canonicalization: Ensure proper canonicalization of the XML document before signature verification. Different canonicalization algorithms can produce different output for the same XML document, potentially leading to verification errors. Use a secure and consistent canonicalization method.
    • XPath Evaluation: Carefully scrutinize XPath expressions used for signature verification. Ensure that they are not vulnerable to manipulation or injection attacks.
    • Transformations: Thoroughly audit and restrict the transformations allowed during signature verification. Only allow transformations that are strictly necessary.
  • Monitoring and Logging: Implement robust monitoring and logging to detect suspicious activity related to XML signature verification. Monitor for unusual patterns, errors, or unexpected behavior.
  • WAF (Web Application Firewall): If applicable, configure a WAF to detect and block potentially malicious XML payloads. Look for signatures of known XML injection or signature wrapping attacks.
  • Isolate Sensitive Operations: Isolate operations that rely on XML signature verification in a secure environment with limited privileges. This reduces the potential impact if an attacker is able to bypass the signature verification.

6. Implementation Details:

  • Node.js npm: Use npm to upgrade the xml-crypto package:

    npm install xml-crypto@latest  # Installs the latest version (including fixes)

    Or, specify the specific patched version:

    npm install [email protected] npm install [email protected] npm install [email protected]

  • Yarn: Use yarn to upgrade the xml-crypto package:

    yarn add xml-crypto@latest

    Or, specify the specific patched version:

    yarn add [email protected] yarn add [email protected] yarn add [email protected]

  • Code Review: After upgrading, conduct a code review to ensure that the xml-crypto library is used correctly and that all signature verification logic is secure. Pay close attention to how XPath expressions are constructed and how transformations are handled.

7. Long-Term Strategy:

  • Dependency Management: Implement a robust dependency management strategy to ensure that all third-party libraries are kept up-to-date with the latest security patches. Use tools like npm audit or yarn audit to identify and address vulnerabilities in your dependencies.
  • Security Audits: Conduct regular security audits of your application and its dependencies. Include penetration testing specifically targeted at XML signature verification logic.
  • Stay Informed: Monitor security advisories and vulnerability databases (e.g., NVD, GitHub Security Advisories) for new vulnerabilities affecting your application and its dependencies.

8. Communication Plan:

  • Internal Communication: Inform relevant stakeholders (developers, security team, system administrators) about the vulnerability and the remediation plan.
  • External Communication: If your application is publicly accessible, consider notifying your users about the vulnerability and the steps you are taking to address it.

9. Disclaimer:

This remediation/mitigation strategy is based on the information provided and general security best practices. It is essential to conduct a thorough assessment of your specific environment and tailor the strategy accordingly. Consult with security experts if needed.

Assigner

Date

  • Published Date: 2025-03-14 17:15:53
  • Updated Date: 2025-03-15 21:15:35

More Details

CVE-2025-29774