Summary
xml-crypto's HMAC-SHA1 signatures can bypass validation via key confusion
Workarounds
The recommendation is to upgrade. In case that is not possible remove the 'http://www.w3.org/2000/09/xmldsig#hmac-sha1' entry from SignedXml.SignatureAlgorithms.
Impact
An attacker can inject an HMAC-SHA1 signature that is valid using only knowledge of the RSA public key. This allows bypassing signature validation.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Version 2.0.0 has the fix.
Frequently Asked Questions
- What is GHSA-C27R-X354-4M68? GHSA-C27R-X354-4M68 is a high-severity improper authentication vulnerability in xml-crypto (npm), affecting versions <= 1.5.3. It is fixed in 2.0.0. The application does not adequately verify the identity of a user, device, or process before granting access.
- Which versions of xml-crypto are affected by GHSA-C27R-X354-4M68? xml-crypto (npm) versions <= 1.5.3 is affected.
- Is there a fix for GHSA-C27R-X354-4M68? Yes. GHSA-C27R-X354-4M68 is fixed in 2.0.0. Upgrade to this version or later.
- Is GHSA-C27R-X354-4M68 exploitable, and should I be worried? Whether GHSA-C27R-X354-4M68 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-C27R-X354-4M68 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-C27R-X354-4M68? Upgrade
xml-cryptoto 2.0.0 or later.