CVE-2024-32962
CVE-2024-32962
Weakness (CWE)
CVSS Vector
v3.1- Attack Vector
- Network
- Attack Complexity
- Low
- Privileges Required
- None
- User Interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Description
xml-crypto is an xml digital signature and encryption library for Node.js. In affected versions the default configuration does not check authorization of the signer, it only checks the validity of the signature per section 3.2.2 of the w3 xmldsig-core-20080610 spec. As such, without additional validation steps, the default configuration allows a malicious actor to re-sign an XML document, place the certificate in a `<KeyInfo />` element, and pass `xml-crypto` default validation checks. As a result `xml-crypto` trusts by default any certificate provided via digitally signed XML document's `<KeyInfo />`. `xml-crypto` prefers to use any certificate provided via digitally signed XML document's `<KeyInfo />` even if library was configured to use specific certificate (`publicCert`) for signature verification purposes. An attacker can spoof signature verification by modifying XML document and replacing existing signature with signature generated with malicious private key (created by attacker) and by attaching that private key's certificate to `<KeyInfo />` element. This vulnerability is combination of changes introduced to `4.0.0` on pull request 301 / commit `c2b83f98` and has been addressed in version 6.0.0 with pull request 445 / commit `21201723d`. Users are advised to upgrade. Users unable to upgrade may either check the certificate extracted via `getCertFromKeyInfo` against trusted certificates before accepting the results of the validation or set `xml-crypto's getCertFromKeyInfo` to `() => undefined` forcing `xml-crypto` to use an explicitly configured `publicCert` or `privateKey` for signature verification.
Comprehensive Technical Analysis of CVE-2024-32962
1. Vulnerability Assessment and Severity Evaluation
CVE ID: CVE-2024-32962 CVSS Score: 10
The vulnerability in the xml-crypto library for Node.js is critical, as indicated by its CVSS score of 10. This score reflects the high severity due to the potential for complete trust subversion in XML digital signatures. The default configuration of xml-crypto does not validate the authorization of the signer, only the validity of the signature. This oversight allows an attacker to re-sign an XML document with a malicious certificate, effectively bypassing the intended security checks.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Signature Spoofing: An attacker can modify an XML document, replace the existing signature with one generated using a malicious private key, and attach the corresponding certificate to the
<KeyInfo />element. - Certificate Trust Subversion: The library trusts any certificate provided in the
<KeyInfo />element, even if a specific certificate is configured for verification.
Exploitation Methods:
- Re-signing XML Documents: By exploiting the lack of authorization checks, an attacker can re-sign XML documents with their own private key and certificate.
- Bypassing Configured Certificates: Even if a specific certificate is configured for verification, the library will prefer the certificate provided in the
<KeyInfo />element, allowing the attacker to bypass this configuration.
3. Affected Systems and Software Versions
Affected Versions:
- The vulnerability affects versions of
xml-cryptofrom 4.0.0 to 5.x.x. - The issue was introduced in version 4.0.0 via pull request 301 and commit
c2b83f98.
Fixed Version:
- The vulnerability has been addressed in version 6.0.0 with pull request 445 and commit
21201723d.
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Upgrade: Users are strongly advised to upgrade to
xml-cryptoversion 6.0.0 or later. - Certificate Validation: For users unable to upgrade, it is recommended to check the certificate extracted via
getCertFromKeyInfoagainst trusted certificates before accepting the validation results. - Configuration Adjustment: Set
xml-crypto's getCertFromKeyInfoto() => undefinedto force the library to use an explicitly configuredpublicCertorprivateKeyfor signature verification.
Long-term Mitigation:
- Regular Audits: Conduct regular security audits of third-party libraries and dependencies.
- Patch Management: Implement a robust patch management process to ensure timely updates and patches.
5. Impact on Cybersecurity Landscape
The vulnerability highlights the importance of thorough validation and authorization checks in digital signature libraries. The reliance on default configurations without additional security measures can lead to severe trust issues, underscoring the need for comprehensive security testing and validation in software development.
6. Technical Details for Security Professionals
Technical Overview:
- Library Functionality:
xml-cryptois used for XML digital signatures and encryption in Node.js applications. - Vulnerability Root Cause: The default configuration does not check the authorization of the signer, only the validity of the signature. This allows an attacker to re-sign an XML document with a malicious certificate.
- Specific Commits:
- Introduced in: Commit
c2b83f98in version 4.0.0. - Fixed in: Commit
21201723din version 6.0.0.
- Introduced in: Commit
References:
- GitHub Commit 21201723d
- GitHub Commit c2b83f98
- GitHub Pull Request 301
- GitHub Pull Request 445
- GitHub Security Advisory
- W3C XML Signature Core
Conclusion:
The vulnerability in xml-crypto underscores the critical importance of robust validation mechanisms in digital signature libraries. Organizations using affected versions should prioritize upgrading to the patched version or implementing the recommended mitigation strategies to prevent potential exploitation. Regular security audits and a proactive approach to patch management are essential to maintaining a secure cybersecurity posture.