CyberSecBulletin
CVE-2024-46984NVD status: Analyzed

app-referencevalidator: Improper Restriction of XML External Entity Reference

Published Updated By the CyberSecBulletin desk

CVE-2024-46984 is a critical-severity improper restriction of XML external entity reference vulnerability in app-referencevalidator from Gematik, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.5.1 as the first without the flaw, so updating app-referencevalidator to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.64% chance of exploitation within 30 days, higher than 51% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update app-referencevalidator to 2.5.1 or a later version.
  2. Update Reference Validator to 2.5.1 or a later version.
  3. Read the advisory on github.com for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Gematikapp-referencevalidator< 2.5.1; before 2.5.12.5.1
GematikReference Validatorbefore 2.5.12.5.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.6HighCNA (github.com)
CVSS 3.19.8CriticalNVD

Official description

The reference validator is a tool to perform advanced validation of FHIR resources for TI applications and interoperability standards. The profile location routine in the referencevalidator commons package is vulnerable to `XML External Entities` attack due to insecure defaults of the used Woodstox WstxInputFactory. A malicious XML resource can lead to network requests issued by referencevalidator and thus to a `Server Side Request Forgery` attack. The vulnerability impacts applications which use referencevalidator to process XML resources from untrusted sources. The problem has been patched with the 2.5.1 version of the referencevalidator. Users are strongly recommended to update to this version or a more recent one. A pre-processing or manual analysis of input XML resources on existence of DTD definitions or external entities can mitigate the problem.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: 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.

How developers prevent this class of flaw

  • Many XML parsers and validators can be configured to disable external entity expansion.

More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Restriction of XML External Entity Reference vulnerabilities

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