CyberSecBulletin
CVE-2024-28198NVD status: Analyzed

OpenOLAT: Improper Restriction of XML External Entity Reference

CVE-2024-28198 is a high-severity improper restriction of XML external entity reference vulnerability in OpenOLAT, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected OpenOLAT versions: < 18.1.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of OpenOLAT 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
OpenOLATOpenOLAT< 18.1.6Not 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
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.14.6MediumCNA (github.com)
CVSS 3.17.5HighNVD

Official description

OpenOlat is an open source web-based e-learning platform for teaching, learning, assessment and communication. By manually manipulating http requests when using the draw.io integration it is possible to read arbitrary files as the configured system user and SSRF. The problem is fixed in version 18.1.6 and 18.2.2. It is advised to upgrade to the latest version of 18.1.x or 18.2.x. Users unable to upgrade may work around this issue by disabling the Draw.io module or the entire REST API which will secure the system.

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 OpenOLAT

All OpenOLAT vulnerabilities

Recent Improper Restriction of XML External Entity Reference vulnerabilities

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