CyberSecBulletin
CVE-2023-4562NVD status: Modified

MELSEC-F Series FX3U-16MT/ES: Improper Authentication

CVE-2023-4562 is a critical-severity improper authentication vulnerability in MELSEC-F Series FX3U-16MT/ES from Mitsubishi Electric, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected MELSEC-F Series FX3U-16MT/ES versions: all versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.21% chance of exploitation within 30 days, higher than 69% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of MELSEC-F Series FX3U-16MT/ES 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 ElectricMELSEC-F Series FX3U-16MT/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-32MT/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-48MT/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-64MT/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-80MT/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-128MT/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-16MR/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-32MR/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-48MR/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-64MR/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-80MR/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-128MR/ESall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-16MT/ESSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-32MT/ESSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-48MT/ESSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-64MT/ESSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-80MT/ESSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-128MT/ESSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-16MT/DSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-32MT/DSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-48MT/DSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-64MT/DSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-80MT/DSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-128MT/DSall versionsNot stated
Mitsubishi ElectricMELSEC-F Series FX3U-16MR/DSall versionsNot stated

Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. 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
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.19.1CriticalCNA (yd.MitsubishiElectric.co.jp)
CVSS 3.19.1CriticalNVD

Official description

Improper Authentication vulnerability in Mitsubishi Electric Corporation MELSEC-F Series main modules allows a remote unauthenticated attacker to obtain sequence programs from the product or write malicious sequence programs or improper data in the product without authentication by sending illegitimate messages.

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

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

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 MELSEC-F Series FX3U-16MT/ES

All MELSEC-F Series FX3U-16MT/ES vulnerabilities

Recent Improper Authentication vulnerabilities

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