GHSA-9p8x-f768-wp2g xml-crypto Vulnerable to XML Signature Verification Bypass via Multiple SignedInfo References

• npm xml-crypto: >= 4.0.0, < 6.0.1 → fixed in 6.0.1 • npm xml-crypto: >= 3.0.0, < 3.2.1 → fixed in 3.2.1 • npm xml-crypto: < 2.1.6 → fixed in 2.1.6

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 forgeddigestvalue realdigestvalue ``` 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 } ```