CyberSecBulletin
CVE-2024-51132NVD status: Deferred

hapi_fhir: Improper Restriction of XML External Entity Reference

Published Updated By the CyberSecBulletin desk

CVE-2024-51132 is a critical-severity improper restriction of XML external entity reference vulnerability in hapi_fhir from FHIR, 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 6.4.0 as the first without the flaw, so updating hapi_fhir to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.9% chance of exploitation within 30 days, higher than 80% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update hapi_fhir to 6.4.0 or a later version.
  2. 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
Fhirhapi_fhirbefore 6.4.06.4.0

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 CISA (ADP).

Official description

An XML External Entity (XXE) vulnerability in HAPI FHIR before v6.4.0 allows attackers to access sensitive information or execute arbitrary code via supplying a crafted request containing malicious XML entities.

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: poc, automatable: yes, technical impact: total).
  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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