CyberSecBulletin
CVE-2023-6943NVD status: Modified

EZSocket: Use of Externally-Controlled Input to Select Classes or Code

Published Updated By the CyberSecBulletin desk

CVE-2023-6943 is a critical-severity use of externally-controlled input to select classes or code vulnerability in EZSocket from Mitsubishi Electric, 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 EZSocket versions: 3.0 to 5.92. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.13% chance of exploitation within 30 days, higher than 82% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of EZSocket you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on mitsubishielectric.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
Mitsubishi ElectricEZSocket3.0 to 5.92Not stated
Mitsubishi ElectricGT Designer3 Version1(GOT1000)1.325P and priorNot stated
Mitsubishi ElectricGT Designer3 Version1(GOT2000)1.320J and priorNot stated
Mitsubishi ElectricGX Works21.11M to 1.626CNot stated
Mitsubishi ElectricGX Works31.106L and priorNot stated
Mitsubishi ElectricMELSOFT Navigator1.04E to 2.102GNot stated
Mitsubishi ElectricMT Works21.190Y and priorNot stated
Mitsubishi ElectricMX Component4.00A to 5.007HNot stated
Mitsubishi ElectricMX OPC Server DA/UAall versionsNot stated
Mitsubishi ElectricFr Configurator2Not specified in the recordNot stated
Mitsubishi ElectricGot1000Not specified in the recordNot stated
Mitsubishi ElectricGot2000Not specified in the recordNot stated
Mitsubishi ElectricMc Works64Not specified in the recordNot 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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalCNA (yd.MitsubishiElectric.co.jp)
CVSS 3.19.8CriticalNVD

Official description

Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vulnerability in Mitsubishi Electric Corporation EZSocket versions 3.0 to 5.92, GT Designer3 Version1(GOT1000) versions 1.325P and prior, GT Designer3 Version1(GOT2000) versions 1.320J and prior, GX Works2 versions 1.11M to 1.626C, GX Works3 versions 1.106L and prior, MELSOFT Navigator versions 1.04E to 2.102G, MT Works2 versions 1.190Y and prior, MX Component versions 4.00A to 5.007H and MX OPC Server DA/UA all versions allows a remote unauthenticated attacker to execute a malicious code by RPC with a path to a malicious library while connected to the products.

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

The underlying weakness: Use of Externally-Controlled Input to Select Classes or Code

The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code.

How developers prevent this class of flaw

  • Refactor your code to avoid using reflection.
  • Do not use user-controlled inputs to select and load classes or code.
  • Apply strict input validation by using allowlists or indirect selection to ensure that the user is only selecting allowable classes or code.

More Use of Externally-Controlled Input to Select Classes or Code vulnerabilities (CWE-470)

Timeline

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

References

Third-party and government advisories

Other vulnerabilities in EZSocket

All EZSocket vulnerabilities

Recent Use of Externally-Controlled Input to Select Classes or Code vulnerabilities

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