Описание
xml-crypto vulnerable to XML signature verification bypass due improper verification of signature/signature spoofing
Summary
Default configuration does not check authorization of the signer, it only checks the validity of the signature per section 3.2.2 of https://www.w3.org/TR/2008/REC-xmldsig-core-20080610/#sec-CoreValidation. 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.
Details
Affected xml-crypto versions between versions >= 4.0.0 and < 6.0.0.
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.
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.
Vulnerability is combination of changes introduced to 4.0.0 at
- https://github.com/node-saml/xml-crypto/pull/301
- https://github.com/node-saml/xml-crypto/commit/c2b83f984049edb68ad1d7c6ad0739ec92af11ca
Changes at PR provided default method to extract certificate from signed XML document.
- https://github.com/node-saml/xml-crypto/blob/c2b83f984049edb68ad1d7c6ad0739ec92af11ca/lib/signed-xml.js#L405-L414
- https://github.com/node-saml/xml-crypto/blob/c2b83f984049edb68ad1d7c6ad0739ec92af11ca/lib/signed-xml.js#L334
and changes at PR prefer output of that method to be used as certificate for signature verification even in the case when library is configured to use specific/pre-configured signingCert
Name of the signingCert was changed later (but prior to 4.0.0 release) to publicCert:
- https://github.com/node-saml/xml-crypto/commit/78329fbae34c9b25ba25882604e960f506d7c0e7
- https://github.com/node-saml/xml-crypto/blob/78329fbae34c9b25ba25882604e960f506d7c0e7/lib/signed-xml.js#L507
Issue was fixed to 6.0.0 by disabling implicit usage of default getCertFromKeyInfo implementation:
- https://github.com/node-saml/xml-crypto/pull/445
- https://github.com/node-saml/xml-crypto/commit/21201723d2ca9bc11288f62cf72552b7d659b000
Possible workarounds for versions 4.x and 5.x:
- Check the certificate extracted via
getCertFromKeyInfoagainst trusted certificates before accepting the results of the validation. - Set
xml-crypto'sgetCertFromKeyInfoto() => undefinedforcingxml-cryptoto use an explicitly configuredpublicCertorprivateKeyfor signature verification.
PoC
https://github.com/node-saml/xml-crypto/discussions/399
Impact
An untrusted certificate can be used to pass a malicious XML payload through an improperly configured installation of xml-crypto.
Ссылки
- https://github.com/node-saml/xml-crypto/security/advisories/GHSA-2xp3-57p7-qf4v
- https://nvd.nist.gov/vuln/detail/CVE-2024-32962
- https://github.com/node-saml/xml-crypto/pull/301
- https://github.com/node-saml/xml-crypto/pull/445
- https://github.com/node-saml/xml-crypto/commit/21201723d2ca9bc11288f62cf72552b7d659b000
- https://github.com/node-saml/xml-crypto/commit/c2b83f984049edb68ad1d7c6ad0739ec92af11ca
- https://github.com/node-saml/xml-crypto/discussions/399
- https://security.netapp.com/advisory/ntap-20240705-0003
- https://www.w3.org/TR/2008/REC-xmldsig-core-20080610/#sec-CoreValidation
Пакеты
xml-crypto
>= 4.0.0, < 6.0.0
6.0.0
Связанные уязвимости
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 atta...
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 attacke
Уязвимость библиотеки цифровой подписи и шифрования XML для Node.js xml-crypto, связанная с некорректной проверкой криптографической подписи, позволяющая нарушителю подделать цифровую подпись