CyberSecBulletin
CVE-2023-38693NVD status: Deferred

Lucee: Improper Restriction of XML External Entity Reference

Published Updated By the CyberSecBulletin desk

CVE-2023-38693 is a critical-severity improper restriction of XML external entity reference vulnerability in Lucee, 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. Affected Lucee versions: >= 5.4.0.0, < 5.4.3.2; >= 5.3.12.0, < 5.3.12.1; < 5.3.7.59, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Lucee you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. 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
LuceeLucee>= 5.4.0.0, < 5.4.3.2; >= 5.3.12.0, < 5.3.12.1; < 5.3.7.59; >= 5.3.8.0, < 5.3.8.236; >= 5.3.9.0, < 5.3.9.173Not stated

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 CNA (github.com).

Official description

Lucee Server (or simply Lucee) is a dynamic, Java based, tag and scripting language used for rapid web application development. The Lucee REST endpoint is vulnerable to RCE via an XML XXE attack. This vulnerability is fixed in Lucee 5.4.3.2, 5.3.12.1, 5.3.7.59, 5.3.8.236, and 5.3.9.173.

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: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Lucee

All Lucee vulnerabilities

Recent Improper Restriction of XML External Entity Reference vulnerabilities

Spotted an error? Tell us.