CVE-2025-29774

xml-crypto is an XML digital signature and encryption library for Node.js. An attacker may be able to exploit a vulnerability in versions prior to 6.0.1, 3.2.1, and 2.1.6 to bypass authentication or authorization mechanisms in systems that rely on xml-crypto for verifying signed XML documents. The vulnerability allows an attacker to modify a valid signed XML message in a way that still passes signature verification checks. For example, it could be used to alter critical identity or access control attributes, enabling an attacker with a valid account to escalate privileges or impersonate another user. Users of versions 6.0.0 and prior should upgrade to version 6.0.1 to receive a fix. Those who are still using v2.x or v3.x should upgrade to patched versions 2.1.6 or 3.2.1, respectively.

xml-crypto is an XML digital signature and encryption library for Node.js. An attacker may be able to exploit a vulnerability in versions prior to 6.0.1, 3.2.1, and 2.1.6 to bypass authentication or authorization mechanisms in systems that rely on xml-crypto for verifying signed XML documents. The vulnerability allows an attacker to modify a valid signed XML message in a way that still passes signature verification checks. For example, it could be used to alter critical identity or access control attributes, enabling an attacker with a valid account to escalate privileges or impersonate another user. Users of versions 6.0.0 and prior should upgrade to version 6.0.1 to receive a fix. Those who are still using v2.x or v3.x should upgrade to patched versions 2.1.6 or 3.2.1, respectively.

# Impact An attacker may be able to exploit this vulnerability to bypass authentication or authorization mechanisms in systems that rely on xml-crypto for verifying signed XML documents. The vulnerability allows an attacker to modify a valid signed XML message in a way that still passes signature verification checks. For example, it could be used to alter critical identity or access control attributes, enabling an attacker with a valid account to escalate privileges or impersonate another user. # Patches All versions <= 6.0.0 are affected. Please upgrade to version 6.0.1. If you are still using v2.x or v3.x please upgrade to the associated patch version. # Indicators of Compromise When logging XML payloads, check for the following indicators. If the payload includes encrypted elements, ensure you analyze the decrypted version for a complete assessment. (If encryption is not used, analyze the original XML document directly). This applies to various XML-based authentication and authorization flows, such as SAML Response payloads. ### Multiple SignedInfo Nodes There should not be more than one SignedInfo node inside a Signature. If you find multiple SignedInfo nodes, it could indicate an attack. ```xml <Signature> <SomeNode> <SignedInfo> <Reference URI="somefakereference"> <DigestValue>forgeddigestvalue</DigestValue> </Reference> </SignedInfo> </SomeNode> <SignedInfo> <Reference URI="realsignedreference"> <DigestValue>realdigestvalue</DigestValue> </Reference> </SignedInfo> </SignedInfo> </Signature> ``` ### Code to test Pass in the decrypted version of the document ```js decryptedDocument = ... // yours to implement // This check is per-Signature node, not per-document const signedInfoNodes = xpath.select(".//*[local-name(.)='SignedInfo']", signatureNode); if (signedInfoNodes.length === 0) { // Not necessarily a compromise, but invalid. Should contain exactly one SignedInfo node // Yours to implement } if (signedInfoNodes.length > 1) { // Compromise detected, yours to implement } ```

# Impact An attacker may be able to exploit this vulnerability to bypass authentication or authorization mechanisms in systems that rely on xml-crypto for verifying signed XML documents. The vulnerability allows an attacker to modify a valid signed XML message in a way that still passes signature verification checks. For example, it could be used to alter critical identity or access control attributes, enabling an attacker with a valid account to escalate privileges or impersonate another user. # Patches All versions <= 6.0.0 are affected. Please upgrade to version 6.0.1. If you are still using v2.x or v3.x please upgrade to the associated patch version. # Indicators of Compromise When logging XML payloads, check for the following indicators. If the payload includes encrypted elements, ensure you analyze the decrypted version for a complete assessment. (If encryption is not used, analyze the original XML document directly). This applies to various XML-based authentication and authorization flows, such as SAML Response payloads. ### Multiple SignedInfo Nodes There should not be more than one SignedInfo node inside a Signature. If you find multiple SignedInfo nodes, it could indicate an attack. ```xml <Signature> <SomeNode> <SignedInfo> <Reference URI="somefakereference"> <DigestValue>forgeddigestvalue</DigestValue> </Reference> </SignedInfo> </SomeNode> <SignedInfo> <Reference URI="realsignedreference"> <DigestValue>realdigestvalue</DigestValue> </Reference> </SignedInfo> </SignedInfo> </Signature> ``` ### Code to test Pass in the decrypted version of the document ```js decryptedDocument = ... // yours to implement // This check is per-Signature node, not per-document const signedInfoNodes = xpath.select(".//*[local-name(.)='SignedInfo']", signatureNode); if (signedInfoNodes.length === 0) { // Not necessarily a compromise, but invalid. Should contain exactly one SignedInfo node // Yours to implement } if (signedInfoNodes.length > 1) { // Compromise detected, yours to implement } ```

xml-crypto es una librería de firma digital y cifrado XML para Node.js. Un atacante podría explotar una vulnerabilidad en versiones anteriores a la 6.0.1, 3.2.1 y 2.1.6 para eludir los mecanismos de autenticación o autorización en sistemas que dependen de xml-crypto para verificar documentos XML firmados. Esta vulnerabilidad permite a un atacante modificar un mensaje XML firmado válido de forma que aún supere las comprobaciones de verificación de firma. Por ejemplo, podría utilizarse para alterar atributos críticos de identidad o control de acceso, lo que permitiría a un atacante con una cuenta válida escalar privilegios o suplantar la identidad de otro usuario. Los usuarios de las versiones 6.0.0 y anteriores deben actualizar a la versión 6.0.1 para obtener una corrección. Quienes aún utilicen las versiones 2.x o 3.x deben actualizar a las versiones 2.1.6 o 3.2.1, respectivamente.